Maize Adaptability to Heat Stress under Changing Climate

*Ayman EL Sabagh, Akbar Hossain, Muhammad Aamir Iqbal, Celaleddin Barutçular, Mohammad Sohidul Islam, Fatih Çiğ, Murat Erman, Oksana Sytar, Marian Brestic, Allah Wasaya, Tasmiya Jabeen, Maham Asif Bukhari, Muhammad Mubeen, Habib-ur-Rehman Athar, Faraz Azeem, Hakki Akdeniz, Ömer Konu*ş*kan, Ferhat Kizilgeci, Muhammad Ikram, Sobhy Sorour, Wajid Nasim, Mabrouk Elsabagh, Muhammad Rizwan, Ram Swaroop Meena, Shah Fahad, Akihiro Ueda, Liyun Liu and Hirofumi Saneoka*

### **Abstract**

The rapidly increasing human population is an alarming issue and would need more food production under changing climate. Abiotic stresses like heat stress and temperature fluctuation are becoming key issues to be addressed for boosting crop production. Maize growth and productivity are sensitive to temperature fluctuations. Grain yield losses in maize from heat stress are expected to increase owing to higher temperatures during the growing season. This situation demands the development of maize hybrids tolerant to heat and drought stresses without compromising grain yield under stress conditions. The chapter aimed to assess the updates on the influence of high-temperature stress (HTS) on the physio-biochemical processes in plants and to draw an association between yield components and heat stress on maize. Moreover, exogenous applications of protectants, antioxidants, and signaling molecules induce HTS tolerance in maize plants and could help the plants cope with HTS by scavenging reactive oxygen species, upregulation of antioxidant enzymes, and protection of cellular membranes by the accrual of compatible osmolytes. It is expected that a better thought of the physiological basis of HTS tolerance in maize plants will help to develop HTS maize cultivars. Developing HTS-tolerant maize varieties may ensure crops production sustainability along with promoting food and feed security under changing climate.

**Keywords:** corn, exogenous applications, heat tolerance, grain quality, grain yield, changing climate

### **1. Introduction**

Since the turn of the twentieth century, the air temperature has risen, expected to proceed to rise as a result of climatic variability. These rises in temperatures may trigger high-temperature stress (HTS): serious damage to plants [1, 2]. As a result, food and feed security have become a crucial challenge under current prevailing agro-climatic conditions [3–5]. Climate modeling has indicated that high temperature during the day and night is threatening global agriculture production system [6]. The result is that maize crop yield is reduced globally [7, 8]. Maize is one of the important crops being cultivated globally with a wide range of uses, and it is an important food crop in the world [9–11], it has been primarily aimed for increasing yield, quality, and stability under different environments [12–15]. Maize is an important component of human food, animal feed, and biofuel industries [5]. It ranks top among cereal crops globally and becomes raw material of numerous food and feed industries. Among growth limiting factors, heat stress has a major effect on maize growth and nutrient composition at different developmental stages. Since several abiotic stresses occur simultaneously, such as drought stress and heat stress, the development of improved breeding procedures is essential for increasing the maize productivity and quality [16]. There is a crucial need for further research to develop maize genotypes tolerant to high temperature and drought stress.

Various physiological and biochemical processes govern plant growth and yield. Stomatal conductance, for example, regulates water loss as transpiration as well as an influx of CO2 for its fixation in the Calvin cycle. Several researchers had suggested that the stomatal conductance is an important indirect heat-tolerant selection criterion in crops [17]. Similarly, osmoprotectants and chaperone proteins got an important part in the adaptive reaction of maize to heat stress and combined stresses. Moreover, leaf senescence-related proteins enhance maize tolerance to combined heat and drought stress [18]. Introgression of these traits in locally acclimated maize hybrids through potential donor hybrids helps in developing maize hybrids tolerant to heat and drought stress. Moreover, identification of donor genotypes possessing favorable traits is important in heat stress breeding programs [19]. Therefore, the present review aimed to evaluate the updates on the effect of heat stress on different plant developmental stages, some physiological and biochemical traits, yield and yield traits of maize. Moreover, this review included updates on various strategies used to improve crop tolerance against heat stress including, conventional breeding strategies, management practices, shotgun approaches, and molecular biology-based strategies. Given the critical analysis of success and limitations for improving maize crop productivity under heat stress, future directions for research are also suggested.

### **2. Adverse effects of heat stress on growth, development, and yield performance of maize**

### **2.1 Morpho-physiological responses**

Temperature above 350 C for a prolonged period is considered unfavorable for crop growth and development and, particularly 400 C during flowering and grain filling have severe negative impacts on grain yield [5]. Plants under heat stress exhibited significantly reduced stomatal conductance resulting in a reduced rate of photosynthesis. Excessive heat also causes a reduction in net photosynthesis, leaf area, reduced biomass accumulation and seed weight [20]. However, heattolerant maize varieties that produced the highest metabolites are not usually high

**165**

*Maize Adaptability to Heat Stress under Changing Climate*

yielding varieties. The heat-tolerant maize varieties are usually characterized by

yield. Therefore, several factors should be put into consideration when selecting for heat tolerance in maize. At the cellular level, HTS triggers the appearance of certain genes and increases the accumulation of certain metabolites that may enhance the heat enduring ability of plants [21]. Generally, remarkable genotypic variations in the stomatal conductance were observed [22, 23]. Stomatal conductance, which is a key trait of the photosynthetic leaf, was significantly influenced by abiotic stresses [24]. Delay canopy senescence due to various light interceptions by green leaf area has been reported to be necessary for high productivity of hybrid maize under normal watering and drought stress [16]. The impinging of high-intensity light to plants can lead to permanent damage to membrane structure [20]. The cell membrane is considered the first physiologically sensitive structure to the high temperature and becomes functionally inactive at heat stress [25]. Membrane function and cell wall stretch have inverse relation [26, 27]. Continuous damage in the biological membrane may downregulate the mobility of water, ions, and soluble organic solid molecules within plant cell membranes; hence carbon of production, transport, and accumulation may be affected by these factors. Membrane stability could be used as an assessment of high-temperature tolerance of plants. It is the most appropriate and convenient test; leakages of electrolytes at a high temperature can be measured

Soil plant analyses development (SPAD) value and grain yield have a significant relationship after anthesis, but no positive association has been noticed during the middle and later grain-filling stages [29, 30]. During HTS, the chlorophyll biosynthesis gene gets downregulated [31]. Experimental observation has suggested that the differences among net photosynthetic ratio after exposure to high temperatures were related to the conversion of the chlorophyll "a" into chlorophyll b ratio; due to low chlorophyll "a" and rapid leaf senescence, the photosynthetic rate is negatively affected [32]. HTS induces several metabolic events at the cellular and subcellular levels. The heat stress influences the production of ROS and oxidative stress as well [33–35]. The antioxidative defense system includes both enzymatic and nonenzymatic antioxidants that are shown to participate in response to the development of

Scientists showed that rather extreme heat intensity could cause serious tissue damage as well as mortality may arise in a matter of minutes and could ultimately be due to a massive collapse of cell organization [36]. Damages can occur just after deep-term exposures at moderate to maximum heat stress. Informal and gradual damages caused by high temperatures include chlorophyll and mitochondrial destruction of enzymatic activity, protein catabolism impairment, protein deterioration, and cell turgidity looseness [37]. As can be seen in studies, with either the introduction of heat-shocked proteins, plants and animals react to high-

temperature pressure [38, 39]. These are intended to avoid species from the harmful impacts of heat stress as well as other sources of pressure [40]. A simple reaction to high-temperature stress is a reduction in regular cellular metabolism. This drop is especially marked at 45°C. The fall in the natural production of protein also goes hand in hand with increased expression and transcription of a fresh set of molecules identified as heat-shock proteins (HSPs) [41]. Previous studies demonstrated that in *Zea mays,* high-temperature stress reduced the protein production and changes the chemical structure of these proteins [42]. Heat stress at the reproduction phase negatively affects the physiology of plants like flower initiation, sourcesink relationship, and falling of pods, which ultimately decreases the number of seeds [43]. High-temperature stress is most crucial for the physiological traits of crop plants. High temperature reduced the number of ears, number of kernels,

, and leaf area index ultimately reduced the

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

the reduced plant height, leaves plant<sup>−</sup><sup>1</sup>

oxidative stress influenced by heat stress [21].

by this test [28].

### *Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

*Plant Stress Physiology*

**1. Introduction**

Since the turn of the twentieth century, the air temperature has risen, expected to proceed to rise as a result of climatic variability. These rises in temperatures may trigger high-temperature stress (HTS): serious damage to plants [1, 2]. As a result, food and feed security have become a crucial challenge under current prevailing agro-climatic conditions [3–5]. Climate modeling has indicated that high temperature during the day and night is threatening global agriculture production system [6]. The result is that maize crop yield is reduced globally [7, 8]. Maize is one of the important crops being cultivated globally with a wide range of uses, and it is an important food crop in the world [9–11], it has been primarily aimed for increasing yield, quality, and stability under different environments [12–15]. Maize is an important component of human food, animal feed, and biofuel industries [5]. It ranks top among cereal crops globally and becomes raw material of numerous food and feed industries. Among growth limiting factors, heat stress has a major effect on maize growth and nutrient composition at different developmental stages. Since several abiotic stresses occur simultaneously, such as drought stress and heat stress, the development of improved breeding procedures is essential for increasing the maize productivity and quality [16]. There is a crucial need for further research to

develop maize genotypes tolerant to high temperature and drought stress. Various physiological and biochemical processes govern plant growth and yield. Stomatal conductance, for example, regulates water loss as transpiration as well as an influx of CO2 for its fixation in the Calvin cycle. Several researchers had suggested that the stomatal conductance is an important indirect heat-tolerant selection criterion in crops [17]. Similarly, osmoprotectants and chaperone proteins got an important part in the adaptive reaction of maize to heat stress and combined stresses. Moreover, leaf senescence-related proteins enhance maize tolerance to combined heat and drought stress [18]. Introgression of these traits in locally acclimated maize hybrids through potential donor hybrids helps in developing maize hybrids tolerant to heat and drought stress. Moreover, identification of donor genotypes possessing favorable traits is important in heat stress breeding programs [19]. Therefore, the present review aimed to evaluate the updates on the effect of heat stress on different plant developmental stages, some physiological and biochemical traits, yield and yield traits of maize. Moreover, this review included updates on various strategies used to improve crop tolerance against heat stress including, conventional breeding strategies, management practices, shotgun approaches, and molecular biology-based strategies. Given the critical analysis of success and limitations for improving maize crop productivity under heat stress, future directions for

**2. Adverse effects of heat stress on growth, development, and yield** 

filling have severe negative impacts on grain yield [5]. Plants under heat stress exhibited significantly reduced stomatal conductance resulting in a reduced rate of photosynthesis. Excessive heat also causes a reduction in net photosynthesis, leaf area, reduced biomass accumulation and seed weight [20]. However, heattolerant maize varieties that produced the highest metabolites are not usually high

C for a prolonged period is considered unfavorable for

C during flowering and grain

**164**

research are also suggested.

**performance of maize**

Temperature above 350

**2.1 Morpho-physiological responses**

crop growth and development and, particularly 400

yielding varieties. The heat-tolerant maize varieties are usually characterized by the reduced plant height, leaves plant<sup>−</sup><sup>1</sup> , and leaf area index ultimately reduced the yield. Therefore, several factors should be put into consideration when selecting for heat tolerance in maize. At the cellular level, HTS triggers the appearance of certain genes and increases the accumulation of certain metabolites that may enhance the heat enduring ability of plants [21]. Generally, remarkable genotypic variations in the stomatal conductance were observed [22, 23]. Stomatal conductance, which is a key trait of the photosynthetic leaf, was significantly influenced by abiotic stresses [24]. Delay canopy senescence due to various light interceptions by green leaf area has been reported to be necessary for high productivity of hybrid maize under normal watering and drought stress [16]. The impinging of high-intensity light to plants can lead to permanent damage to membrane structure [20]. The cell membrane is considered the first physiologically sensitive structure to the high temperature and becomes functionally inactive at heat stress [25]. Membrane function and cell wall stretch have inverse relation [26, 27]. Continuous damage in the biological membrane may downregulate the mobility of water, ions, and soluble organic solid molecules within plant cell membranes; hence carbon of production, transport, and accumulation may be affected by these factors. Membrane stability could be used as an assessment of high-temperature tolerance of plants. It is the most appropriate and convenient test; leakages of electrolytes at a high temperature can be measured by this test [28].

Soil plant analyses development (SPAD) value and grain yield have a significant relationship after anthesis, but no positive association has been noticed during the middle and later grain-filling stages [29, 30]. During HTS, the chlorophyll biosynthesis gene gets downregulated [31]. Experimental observation has suggested that the differences among net photosynthetic ratio after exposure to high temperatures were related to the conversion of the chlorophyll "a" into chlorophyll b ratio; due to low chlorophyll "a" and rapid leaf senescence, the photosynthetic rate is negatively affected [32]. HTS induces several metabolic events at the cellular and subcellular levels. The heat stress influences the production of ROS and oxidative stress as well [33–35]. The antioxidative defense system includes both enzymatic and nonenzymatic antioxidants that are shown to participate in response to the development of oxidative stress influenced by heat stress [21].

Scientists showed that rather extreme heat intensity could cause serious tissue damage as well as mortality may arise in a matter of minutes and could ultimately be due to a massive collapse of cell organization [36]. Damages can occur just after deep-term exposures at moderate to maximum heat stress. Informal and gradual damages caused by high temperatures include chlorophyll and mitochondrial destruction of enzymatic activity, protein catabolism impairment, protein deterioration, and cell turgidity looseness [37]. As can be seen in studies, with either the introduction of heat-shocked proteins, plants and animals react to hightemperature pressure [38, 39]. These are intended to avoid species from the harmful impacts of heat stress as well as other sources of pressure [40]. A simple reaction to high-temperature stress is a reduction in regular cellular metabolism. This drop is especially marked at 45°C. The fall in the natural production of protein also goes hand in hand with increased expression and transcription of a fresh set of molecules identified as heat-shock proteins (HSPs) [41]. Previous studies demonstrated that in *Zea mays,* high-temperature stress reduced the protein production and changes the chemical structure of these proteins [42]. Heat stress at the reproduction phase negatively affects the physiology of plants like flower initiation, sourcesink relationship, and falling of pods, which ultimately decreases the number of seeds [43]. High-temperature stress is most crucial for the physiological traits of crop plants. High temperature reduced the number of ears, number of kernels,

chlorophyll efficiency, firing of leaf, and blasting of the tassel [44]. Climatic stress like high-temperature stress severely reduces the growth and yield of several crops belongs to Leguminosae (Fabaceae). Heat stress severely reduced the physiological growth development and production of *Vigna radiata*. Heat stress reduced dry matter production and other yield attributes [45].

### **2.2 Effect on seed germination and seedling development**

HTS hampers the plant growth; particularly germination and seedling emergence are more sensitive [46]. Stressful environment severely reduces the germination and early seedling growth in several crop plants [47, 48]. However, seeds of sensitive crops exposed to 24 and 48 h moderate heat stress exhibited a higher germination rate. Such an increase in seed germination rate due to short-term exposure to moderate heat stress was attributed to the altered expression of gibberellin and abscisic acid biosynthesis genes [49]. The seedling stage is generally considered as the most sensitive stage to stress in maize development [50]. However, the detrimental impact of water deficit stress on the initial phase of growth and seedling establishment of maize plants cannot be underestimated [51–53].

The appropriate sowing date is important for seed germination and seedling establishment to physiological maturity. The heat-tolerant maize varieties germinated earlier than the non-drought tolerant maize varieties under the critical level of watering. During germination, HTS is associated with an impaired emergency, and a reduced plant stand and plant density [54]. Biochemical components such as soluble sugar and proline increased with increased stress, while starch content and relative water content reduced with increased water deficit [55]. Fluctuations in mean daily temperature (either it is maximum or minimum) disturb seed germination ability [56]. High-temperature stress is the main cause of the reduction in plant yield due to poor germination. [57, 58] studied the impact of high temperature on various developmental phases, especially at seedling emergence in various crop genotypes. Critical periods of stress in maize include seedling establishment stages, rapid growth period, pollination and grain-filling stage. It is proven that in the maize plant with the implementation of stress, not only the leaf area is reduced, but also its growth rate is affected and the appearance of each leaf is delayed [59].

### **2.3 Grain-filling stage**

HTS at the grain-filling stage in spring maize is the main obstacle [60]. Temperature beyond 40°C, mainly during flowering and grain filling has a severe impact on plant grain productivity [5]. Grain filling is highly sensitive to drought and heat, due to the involvement of the array of diverse enzymes and transporters, located in the leaves and seeds [45]. During HTS, the stability of the thylakoid membrane structure is reduced, resulting in degrading chlorophyll, which reduces light energy absorption, transfer, and photosynthetic carbon assimilation, and ultimately photosynthesis is reduced. Inhibited photosynthesis decreases the supply of photosynthates to the grain, leading to a serious reduction of kernel weight and grain yield [60–62]. Delay in the development of reproductive organs might be the result of the reduced cell division and cell elongation processes due to reduced supply of photosynthates and carbohydrate metabolism during the active vegetative growth stages [63].

### **2.4 Yield components and grain yield**

A projection based on the increased daily maximum temperatures concluded that to increase the maize yields by 12% for the period 2016–2035, improved

**167**

**Figure 1.**

*Maize Adaptability to Heat Stress under Changing Climate*

technologies would be needed [64]. Maize plant can face moderate to high temperature, but temperature above 35°C for a long duration is considered unfavorable for crop growth and development, and temperature beyond 40°C, mainly during flowering and grain filling will have a severe impact on plant grain productivity [5]. Meanwhile, early season temperature increases have induced the maize reproductive period to start earlier, developing the risk of water and heat stress. Declines in time to maturation of maize shown of independence of effects to availability of water, the potential of yield which becoming increasingly limited by warming itself [65]. Irrigation regimes were the major determinant of grain yield during the grainfilling stage in maize while significant differences in the number of kernels per row were obtained among irrigation regimes [66]. A large difference in grain yield is caused due to HTS, which is shown in **Figure 1**. Tissue injuries inversely influence the photosynthetic rate during heat stress, which can cause leaf damaging and increase the rate of leaf senescence that largely results in decreasing photosynthetic efficiency [44]. Reduced chlorophyll content, including grain yields and oxidative damages, possibly had a direct correlation under heat stress [5, 67]. Previous research studies indicate that high temperature has a severe effect on the cob growth rate as well as biomass partitioning [68]. Many factors including duration of pollen viability, increased kernel abortion rate, lower the rate of cell division in storage tissue (endosperm), decrease in starch synthesis, downregulate the sink capacity of developing kernel, increased rate of sugar accumulation, kernel development, and less/higher enzyme activities could be responsible for the reduction in kernel per row under heat stress [44, 67]. Stress environment leads to a severe reduction in yield of crop plants probably by disrupting leaf gas exchange properties, which not only limit the size of the source and sink tissues, but the phloem loading, assimilate translocation, and dry matter partitioning are also impaired [46]. Unsuccessful fertilization reduces the seed size and increases flower abortion rate owing to high temperature and it has negative effects on plant reproductive phase [69, 70].

C, is considered suitable for leaf growth, the temperature

C has an inverse relation with leaf growth. Temperature beyond

C is responsible for lower net photosynthetic rate, which further leads to protein aggregation, enzyme inactivation, inhibition of protein synthesis leading to the degradation of protein synthesis [69, 71]. Eventually, an increase in temperature

*Differences in total leaf collars, cumulative leaf area, and grain yield of three corn hybrids grown under* 

*normal Ames, Iowa temperatures and normal +4°C temperatures.*

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

Temperature range 0–35o

range 35–40o

35-40o

### *Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

*Plant Stress Physiology*

ter production and other yield attributes [45].

**2.2 Effect on seed germination and seedling development**

establishment of maize plants cannot be underestimated [51–53].

chlorophyll efficiency, firing of leaf, and blasting of the tassel [44]. Climatic stress like high-temperature stress severely reduces the growth and yield of several crops belongs to Leguminosae (Fabaceae). Heat stress severely reduced the physiological growth development and production of *Vigna radiata*. Heat stress reduced dry mat-

HTS hampers the plant growth; particularly germination and seedling emergence are more sensitive [46]. Stressful environment severely reduces the germination and early seedling growth in several crop plants [47, 48]. However, seeds of sensitive crops exposed to 24 and 48 h moderate heat stress exhibited a higher germination rate. Such an increase in seed germination rate due to short-term exposure to moderate heat stress was attributed to the altered expression of gibberellin and abscisic acid biosynthesis genes [49]. The seedling stage is generally considered as the most sensitive stage to stress in maize development [50]. However, the detrimental impact of water deficit stress on the initial phase of growth and seedling

The appropriate sowing date is important for seed germination and seedling establishment to physiological maturity. The heat-tolerant maize varieties germinated earlier than the non-drought tolerant maize varieties under the critical level of watering. During germination, HTS is associated with an impaired emergency, and a reduced plant stand and plant density [54]. Biochemical components such as soluble sugar and proline increased with increased stress, while starch content and relative water content reduced with increased water deficit [55]. Fluctuations in mean daily temperature (either it is maximum or minimum) disturb seed germination ability [56]. High-temperature stress is the main cause of the reduction in plant yield due to poor germination. [57, 58] studied the impact of high temperature on various developmental phases, especially at seedling emergence in various crop genotypes. Critical periods of stress in maize include seedling establishment stages, rapid growth period, pollination and grain-filling stage. It is proven that in the maize plant with the implementation of stress, not only the leaf area is reduced, but also its growth rate is affected and the appearance of each leaf is delayed [59].

HTS at the grain-filling stage in spring maize is the main obstacle [60]. Temperature beyond 40°C, mainly during flowering and grain filling has a severe impact on plant grain productivity [5]. Grain filling is highly sensitive to drought and heat, due to the involvement of the array of diverse enzymes and transporters, located in the leaves and seeds [45]. During HTS, the stability of the thylakoid membrane structure is reduced, resulting in degrading chlorophyll, which reduces light energy absorption, transfer, and photosynthetic carbon assimilation, and ultimately photosynthesis is reduced. Inhibited photosynthesis decreases the supply of photosynthates to the grain, leading to a serious reduction of kernel weight and grain yield [60–62]. Delay in the development of reproductive organs might be the result of the reduced cell division and cell elongation processes due to reduced supply of photosynthates and carbohydrate metabolism during the active vegetative growth stages [63].

A projection based on the increased daily maximum temperatures concluded

that to increase the maize yields by 12% for the period 2016–2035, improved

**166**

**2.3 Grain-filling stage**

**2.4 Yield components and grain yield**

technologies would be needed [64]. Maize plant can face moderate to high temperature, but temperature above 35°C for a long duration is considered unfavorable for crop growth and development, and temperature beyond 40°C, mainly during flowering and grain filling will have a severe impact on plant grain productivity [5]. Meanwhile, early season temperature increases have induced the maize reproductive period to start earlier, developing the risk of water and heat stress. Declines in time to maturation of maize shown of independence of effects to availability of water, the potential of yield which becoming increasingly limited by warming itself [65]. Irrigation regimes were the major determinant of grain yield during the grainfilling stage in maize while significant differences in the number of kernels per row were obtained among irrigation regimes [66]. A large difference in grain yield is caused due to HTS, which is shown in **Figure 1**. Tissue injuries inversely influence the photosynthetic rate during heat stress, which can cause leaf damaging and increase the rate of leaf senescence that largely results in decreasing photosynthetic efficiency [44]. Reduced chlorophyll content, including grain yields and oxidative damages, possibly had a direct correlation under heat stress [5, 67]. Previous research studies indicate that high temperature has a severe effect on the cob growth rate as well as biomass partitioning [68]. Many factors including duration of pollen viability, increased kernel abortion rate, lower the rate of cell division in storage tissue (endosperm), decrease in starch synthesis, downregulate the sink capacity of developing kernel, increased rate of sugar accumulation, kernel development, and less/higher enzyme activities could be responsible for the reduction in kernel per row under heat stress [44, 67]. Stress environment leads to a severe reduction in yield of crop plants probably by disrupting leaf gas exchange properties, which not only limit the size of the source and sink tissues, but the phloem loading, assimilate translocation, and dry matter partitioning are also impaired [46]. Unsuccessful fertilization reduces the seed size and increases flower abortion rate owing to high temperature and it has negative effects on plant reproductive phase [69, 70]. Temperature range 0–35o C, is considered suitable for leaf growth, the temperature range 35–40o C has an inverse relation with leaf growth. Temperature beyond 35-40o C is responsible for lower net photosynthetic rate, which further leads to protein aggregation, enzyme inactivation, inhibition of protein synthesis leading to the degradation of protein synthesis [69, 71]. Eventually, an increase in temperature

### **Figure 1.**

*Differences in total leaf collars, cumulative leaf area, and grain yield of three corn hybrids grown under normal Ames, Iowa temperatures and normal +4°C temperatures.*

beyond its critical value leads to generating a heat stress that harms the morphological growth, grain yield, and yield-related attributes of two maize cultivars "Xida 319" and "Xida 889" [72].

### **2.5 Quality traits of maize**

Temperatures higher than 35°C negatively affect maize grain quality. Grain quality, which is governed by factors including the duration and rate of grain filling and the availability of assimilates, is negatively influenced under water deficit conditions. Similar negative effects of stress were reported on the grain weight of wheat [15, 73–75]. Variations in flour quality in a hard-grained crop could be related to changes in protein composition due to heat stress during the grain-filling stage [76]. As per the findings of Mousavi et al. [77], heat stress at the flowering stage greatly reduced the starch content due to the reduction in the photosynthetic activities leading to an increase in the grain protein ratio. Usually, maize quality properties are affected by genotypes, environmental factors, and their interactions (**Figure 2**). Therefore, growth and development of maize are dramatically affected by heat stress leading to reduced grain weight with low starch, crude oil, and protein contents [30]. Grain filling is the most environmentally sensitive phase in maize, which strongly affects grain development quantitatively and qualitatively [7, 15]. Oury and Godin [78] reported a negative correlation between protein contents and grain weight in maize under stress conditions. Association analysis revealed that cob length, thousand-grain weight, and protein contents had a significant relationship with grain yield of maize [79].

In the previous study, the starch content in waxy maize grain was decreased, whereas protein content was increased, resulting in the change of grain quality [80]. However, the activities of enzymes involved in the synthesis of starch and protein are still lacking [81]. The qualitative and quantitative characteristics of grain productivity are mainly influenced by the environmental fluctuation and these changes inversely influence the development and maturing of seed that affect the seed-filling process and deposition of reserves [80]. Generally, high impinging of light affects negatively in plant productivity by causing premature senescence, decreased seed-filling duration, and enhancing remobilization of photosynthates from source to sink [82]. These factors combined, mainly lowers plant biomass and productivity, and finally lowers the assimilate production and mobilization of the reserve to different developing crops [83]. Generally, it is predicted that gene controlling cell division gets downregulated due to water stress, which could be responsible for the decreased cell number in cotyledons along with endosperm. However, further research is required to find out the actual

**169**

*Maize Adaptability to Heat Stress under Changing Climate*

mechanisms controlling these events. Probably due to low enzyme efficiency or high km carbohydrate gene gets downregulated in developing seedling, resulting in limited availability of sucrose, finally producing reduced seed size [45]. The time of seed filling reduced in pea, soybean, and white lupin, resulting in smaller grains [84]. Heat stress during grain filling markedly decreased starch accumulation in

High-temperature stress decreases the protein concentration in the wheat seeds during seed formation stage [76]. Carbon and nitrogen transmission in the seed is improved with the maximum temperature but C transfer is reduced by the daily temperature fluctuations [87]. Temperature variability effects are more visible on the size of seed than seed N contents [87]. Size of seed and protein concentration in the seed are inversely proportional to each other [88]. Hightemperature stress reduces seed production, which ultimately declines the seed protein contents [89]. Protein accumulation in the seeds depends upon hightemperature stress [89]. When high-temperature stress occurs at the seed-filling stage it declines the seed protein contents [89]. When wheat crops are exposed to the high-temperature, glutenin protein production is decreased while gliadins protein production remains stable [90]. Seed protein contents of various crops are decreased after imposing the high-temperature stress, but various amino acid concentrations become low [91]. Heat stress damaged the protective layer of seed and food storage tissues of seed, which is why the quality of seed was

**3. Adaptation and management strategies of maize under heat stress**

Enhancement of the antioxidant defense system is an important strategy to scavenge ROS by antioxidant enzymes [92]. Similar to antioxidant defense, phytohormones such as auxin (indole acetic acid, IAA), cytokinins (CKs), abscisic acid (ABA), ethylene (ET), gibberellins (GAs), salicylic acid (SA), brassinosteroids (BRs), and jasmonates (JAs) have key roles in coordinating various signal transduction pathways during the abiotic-stress response [93]. Many studies have shown that altering cultural practices, such as planting rate [94], planting date [95, 96],

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

wheat [85] and rice [86].

*Quality of maize is deteriorated due to heat stress.*

**Figure 3.**

deteriorated (**Figure 3**).

*Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

*Plant Stress Physiology*

319" and "Xida 889" [72].

**2.5 Quality traits of maize**

with grain yield of maize [79].

beyond its critical value leads to generating a heat stress that harms the morphological growth, grain yield, and yield-related attributes of two maize cultivars "Xida

Temperatures higher than 35°C negatively affect maize grain quality. Grain quality, which is governed by factors including the duration and rate of grain filling and the availability of assimilates, is negatively influenced under water deficit conditions. Similar negative effects of stress were reported on the grain weight of wheat [15, 73–75]. Variations in flour quality in a hard-grained crop could be related to changes in protein composition due to heat stress during the grain-filling stage [76]. As per the findings of Mousavi et al. [77], heat stress at the flowering stage greatly reduced the starch content due to the reduction in the photosynthetic activities leading to an increase in the grain protein ratio. Usually, maize quality properties are affected by genotypes, environmental factors, and their interactions (**Figure 2**). Therefore, growth and development of maize are dramatically affected by heat stress leading to reduced grain weight with low starch, crude oil, and protein contents [30]. Grain filling is the most environmentally sensitive phase in maize, which strongly affects grain development quantitatively and qualitatively [7, 15]. Oury and Godin [78] reported a negative correlation between protein contents and grain weight in maize under stress conditions. Association analysis revealed that cob length, thousand-grain weight, and protein contents had a significant relationship

In the previous study, the starch content in waxy maize grain was decreased, whereas protein content was increased, resulting in the change of grain quality [80]. However, the activities of enzymes involved in the synthesis of starch and protein are still lacking [81]. The qualitative and quantitative characteristics of grain productivity are mainly influenced by the environmental fluctuation and these changes inversely influence the development and maturing of seed that affect the seed-filling process and deposition of reserves [80]. Generally, high impinging of light affects negatively in plant productivity by causing premature senescence, decreased seed-filling duration, and enhancing remobilization of photosynthates from source to sink [82]. These factors combined, mainly lowers plant biomass and productivity, and finally lowers the assimilate production and mobilization of the reserve to different developing crops [83]. Generally, it is predicted that gene controlling cell division gets downregulated due to water stress, which could be responsible for the decreased cell number in cotyledons along with endosperm. However, further research is required to find out the actual

**168**

**Figure 2.**

*Quality of maize is influenced by genotype, environment, and their interaction.*

**Figure 3.** *Quality of maize is deteriorated due to heat stress.*

mechanisms controlling these events. Probably due to low enzyme efficiency or high km carbohydrate gene gets downregulated in developing seedling, resulting in limited availability of sucrose, finally producing reduced seed size [45]. The time of seed filling reduced in pea, soybean, and white lupin, resulting in smaller grains [84]. Heat stress during grain filling markedly decreased starch accumulation in wheat [85] and rice [86].

High-temperature stress decreases the protein concentration in the wheat seeds during seed formation stage [76]. Carbon and nitrogen transmission in the seed is improved with the maximum temperature but C transfer is reduced by the daily temperature fluctuations [87]. Temperature variability effects are more visible on the size of seed than seed N contents [87]. Size of seed and protein concentration in the seed are inversely proportional to each other [88]. Hightemperature stress reduces seed production, which ultimately declines the seed protein contents [89]. Protein accumulation in the seeds depends upon hightemperature stress [89]. When high-temperature stress occurs at the seed-filling stage it declines the seed protein contents [89]. When wheat crops are exposed to the high-temperature, glutenin protein production is decreased while gliadins protein production remains stable [90]. Seed protein contents of various crops are decreased after imposing the high-temperature stress, but various amino acid concentrations become low [91]. Heat stress damaged the protective layer of seed and food storage tissues of seed, which is why the quality of seed was deteriorated (**Figure 3**).

### **3. Adaptation and management strategies of maize under heat stress**

Enhancement of the antioxidant defense system is an important strategy to scavenge ROS by antioxidant enzymes [92]. Similar to antioxidant defense, phytohormones such as auxin (indole acetic acid, IAA), cytokinins (CKs), abscisic acid (ABA), ethylene (ET), gibberellins (GAs), salicylic acid (SA), brassinosteroids (BRs), and jasmonates (JAs) have key roles in coordinating various signal transduction pathways during the abiotic-stress response [93]. Many studies have shown that altering cultural practices, such as planting rate [94], planting date [95, 96],

the phenological variation of crop cultivars [60, 95] soil management [97], nutrient management [60], and irrigation [60] can positively or negatively modify maize yield response to climate change.

### **3.1 Avoid high-temperature stress by adjusting the sowing date**

Advancing or delaying the sowing date may be a potent, farmer-friendly and biologically viable strategy to avoid HTS. Earlier findings reported that earlier sowing dates and longer season varieties have overcome the negative effects of climate warming on spring maize yield [95]. Similarly, other findings reported by [98] showed that by changing sowing date from late April to late May, the mean daily temperature decreased 1.7 and 4.3°C whereas the diurnal temperature increased 4.3 and 3.1°C during grain-filling middle stage (16-45 days after silking) and grainfilling late stage (45 days after silking to maturity), respectively.

### **3.2 Optimizing irrigation**

High air temperatures during the crop growing season can reduce harvestable yields. However, crop varieties with improved heat tolerance traits as well as crop management strategies at the farm scale are thus needed for climate change mitigation. Therefore, to mitigate the negative impact of increased growing season temperatures on crop growth and yield, especially in low latitude regions, heat-tolerant crop varieties, as well as modified farm management practices are needed, especially in the areas when irrigation is needed for crop production and irrigation water depends on the underground aquifers [99]. They also observed that applied irrigation at nighttime through subsurface drip reduced the root-zone soil temperature, which helped plant for improving plant growth and yield of corn. Optimizing irrigation has the potential to improve the water use efficiency of maize leading to enhanced heat tolerance [60]. Soil drought stress and atmospheric high temperature in the vegetative growth period could delay the process of growth of spring maize and shorten the reproductive stage, but those get improved when the soil moisture content in the maize field is maintained 65% field capacity by drip irrigation [100].

### **3.3 Accumulation of heat-stress defensive phytohormones in plant tissues**

Plant growth hormones and exogenous chemicals (e.g., ABA and CaCl2) play important roles in strengthening heat tolerance in maize under HTS [60]. Exogenous ABA induces maize to produce HSPs, strengthening PSII heat tolerance [101]. An exogenous CaCl2 increases the maize cell membrane antioxidant capacity to improve heat tolerance [102]. Phytohormones such as auxin (IAA), cytokinins (CKs), abscisic acid (ABA), ethylene (ET), gibberellins (GAs), salicylic acid (SA), brassinosteroids (BRs), and jasmonates (JAs) have key roles in coordinating various signal transduction pathways during the abiotic-stress response [93].

Auxin or indole-3-acetic acid (Aux/IAA) acts as a chemical messenger to communicate cell activities when crops face different environmental stresses, including salinity, drought, waterlogging, extreme temperatures (heat, chilling, and freezing), heavy metals, light (intense and weak), and radiation (UV-A/B) [92, 103, 104]. Cytokinin (CK) is one of them, which functions solely and or with other hormones to mediate different mechanisms within plants in response to environmental fluctuations. During heat stress, protein denaturation and metabolic imbalance are occurred due to the excessive production of ROS. While to survive against heat

**171**

*Maize Adaptability to Heat Stress under Changing Climate*

stress, plants stimulate heat-shock proteins as a protective measure to prevent protein denaturation [105]. For example, the upregulation of heat-shock proteins in tobacco and bentgrass was recorded due to the enhancement of the antioxidant activity as a result of higher CK in plant cells [106]. Besides this, external application of CK inhibits the damage in photosynthesis under heat stress in maize, rice, and passion fruit [107, 108]. Salicylic acid (SA) is a naturally occurring phenolic compound [109] which plays a crucial part in the regulation of growth and development of the plants, and also a defensive mechanism to survive against abiotic stresses [110]. Similar to SA, abscisic acid (ABA) plays a vital role in plants' physiological adjustments such as against abiotic stresses [111, 112] along with increasing seedling growth, endogenous levels of ABA, and reduced oxidative damage to plants due to heat stress. Similarly, Hasanuzzaman et al. [21] observed that ABA is a signaling molecule and also enhance the number of other signaling molecules such as nitric oxide for thermos-tolerance. Similar to other phytohormones, gibberellic acid (GAs) also interacts with other phytohormones in numerous developmental and stimulus-response processes in plants. GAs have been reported to alleviate the adverse effects of abiotic stress in plants, including rice as reported by Yamaguchi [113]. Brassinosteroids (BRs) is a new group of phytohormones, present in almost every part of the plants [114]. Similar to other phytohormones, BRs have shown tremendous potential against the abiotic stress-induced oxidative stress [103]

Inadequate and imbalanced nutrients and impaired soil fertility are associated with mineral-nutrient deficiencies and toxicities [116–118]. Adequate nutrition is essential for the integrity of plant structure and key physiological processes. For example, nitrogen (N) and magnesium are a structural part of chlorophyll and these are needed for photosynthesis. Nitrogen plays a very crucial role in temperature stress tolerance. At higher temperatures, the intensity of light is also very high. So, high light intensity, as a function of high temperature, which affects the uptake of mineral nutrients, ultimately influences the plant growth negatively. Since N plays a major role in the utilization of absorbed light energy and photosynthetic carbon metabolism [119, 120]. Whereas phosphorus is needed for energy production and storage; it is a structural part of nucleic acids and potassium is needed for osmotic regulation and activation of enzymes [117, 118]. Maize physiological function decreases under abiotic stress but can be compensated by nutritional management, for example, adequate potassium fertilizer improves cell membrane stability, turgor pressure, water potential in maize under water-deficit conditions [60]. Thus, a strategy to improve heat tolerance in maize at the grain-filling stage is

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

including high temperature [115].

**3.4 Nutrient management**

to regulate nutrition.

stress conditions [121–123].

**3.5 Selection of high-temperature stress-resistant varieties**

Selection criteria have been proposed in traditional breeding to facilitate the detection of heat-tolerant maize variety. As different varieties respond differently to HTS, breeding heat-tolerant varieties is an effective strategy to improve heat tolerance at the spring maize grain-filling stage [60]. Screening of various cultivars was done to screen the warmness of the plant canopy, stomata behavior of upper most leaf (flag leaf), and photosynthesizing efficiency that are closely related to each other for the production maximum grain production under high-temperature

*Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

*Plant Stress Physiology*

yield response to climate change.

**3.2 Optimizing irrigation**

drip irrigation [100].

the phenological variation of crop cultivars [60, 95] soil management [97], nutrient management [60], and irrigation [60] can positively or negatively modify maize

Advancing or delaying the sowing date may be a potent, farmer-friendly and biologically viable strategy to avoid HTS. Earlier findings reported that earlier sowing dates and longer season varieties have overcome the negative effects of climate warming on spring maize yield [95]. Similarly, other findings reported by [98] showed that by changing sowing date from late April to late May, the mean daily temperature decreased 1.7 and 4.3°C whereas the diurnal temperature increased 4.3 and 3.1°C during grain-filling middle stage (16-45 days after silking) and grain-

High air temperatures during the crop growing season can reduce harvestable yields. However, crop varieties with improved heat tolerance traits as well as crop management strategies at the farm scale are thus needed for climate change mitigation. Therefore, to mitigate the negative impact of increased growing season temperatures on crop growth and yield, especially in low latitude regions, heat-tolerant crop varieties, as well as modified farm management practices are needed, especially in the areas when irrigation is needed for crop production and irrigation water depends on the underground aquifers [99]. They also observed that applied irrigation at nighttime through subsurface drip reduced the root-zone soil temperature, which helped plant for improving plant growth and yield of corn. Optimizing irrigation has the potential to improve the water use efficiency of maize leading to enhanced heat tolerance [60]. Soil drought stress and atmospheric high temperature in the vegetative growth period could delay the process of growth of spring maize and shorten the reproductive stage, but those get improved when the soil moisture content in the maize field is maintained 65% field capacity by

**3.3 Accumulation of heat-stress defensive phytohormones in plant tissues**

Plant growth hormones and exogenous chemicals (e.g., ABA and CaCl2) play important roles in strengthening heat tolerance in maize under HTS [60]. Exogenous ABA induces maize to produce HSPs, strengthening PSII heat tolerance [101]. An exogenous CaCl2 increases the maize cell membrane antioxidant capacity to improve heat tolerance [102]. Phytohormones such as auxin (IAA), cytokinins (CKs), abscisic acid (ABA), ethylene (ET), gibberellins (GAs), salicylic acid (SA), brassinosteroids (BRs), and jasmonates (JAs) have key roles in coordinating various

Auxin or indole-3-acetic acid (Aux/IAA) acts as a chemical messenger to communicate cell activities when crops face different environmental stresses, including salinity, drought, waterlogging, extreme temperatures (heat, chilling, and freezing), heavy metals, light (intense and weak), and radiation (UV-A/B) [92, 103, 104]. Cytokinin (CK) is one of them, which functions solely and or with other hormones to mediate different mechanisms within plants in response to environmental fluctuations. During heat stress, protein denaturation and metabolic imbalance are occurred due to the excessive production of ROS. While to survive against heat

signal transduction pathways during the abiotic-stress response [93].

**3.1 Avoid high-temperature stress by adjusting the sowing date**

filling late stage (45 days after silking to maturity), respectively.

**170**

stress, plants stimulate heat-shock proteins as a protective measure to prevent protein denaturation [105]. For example, the upregulation of heat-shock proteins in tobacco and bentgrass was recorded due to the enhancement of the antioxidant activity as a result of higher CK in plant cells [106]. Besides this, external application of CK inhibits the damage in photosynthesis under heat stress in maize, rice, and passion fruit [107, 108]. Salicylic acid (SA) is a naturally occurring phenolic compound [109] which plays a crucial part in the regulation of growth and development of the plants, and also a defensive mechanism to survive against abiotic stresses [110]. Similar to SA, abscisic acid (ABA) plays a vital role in plants' physiological adjustments such as against abiotic stresses [111, 112] along with increasing seedling growth, endogenous levels of ABA, and reduced oxidative damage to plants due to heat stress. Similarly, Hasanuzzaman et al. [21] observed that ABA is a signaling molecule and also enhance the number of other signaling molecules such as nitric oxide for thermos-tolerance. Similar to other phytohormones, gibberellic acid (GAs) also interacts with other phytohormones in numerous developmental and stimulus-response processes in plants. GAs have been reported to alleviate the adverse effects of abiotic stress in plants, including rice as reported by Yamaguchi [113]. Brassinosteroids (BRs) is a new group of phytohormones, present in almost every part of the plants [114]. Similar to other phytohormones, BRs have shown tremendous potential against the abiotic stress-induced oxidative stress [103] including high temperature [115].

### **3.4 Nutrient management**

Inadequate and imbalanced nutrients and impaired soil fertility are associated with mineral-nutrient deficiencies and toxicities [116–118]. Adequate nutrition is essential for the integrity of plant structure and key physiological processes. For example, nitrogen (N) and magnesium are a structural part of chlorophyll and these are needed for photosynthesis. Nitrogen plays a very crucial role in temperature stress tolerance. At higher temperatures, the intensity of light is also very high. So, high light intensity, as a function of high temperature, which affects the uptake of mineral nutrients, ultimately influences the plant growth negatively. Since N plays a major role in the utilization of absorbed light energy and photosynthetic carbon metabolism [119, 120]. Whereas phosphorus is needed for energy production and storage; it is a structural part of nucleic acids and potassium is needed for osmotic regulation and activation of enzymes [117, 118]. Maize physiological function decreases under abiotic stress but can be compensated by nutritional management, for example, adequate potassium fertilizer improves cell membrane stability, turgor pressure, water potential in maize under water-deficit conditions [60]. Thus, a strategy to improve heat tolerance in maize at the grain-filling stage is to regulate nutrition.

### **3.5 Selection of high-temperature stress-resistant varieties**

Selection criteria have been proposed in traditional breeding to facilitate the detection of heat-tolerant maize variety. As different varieties respond differently to HTS, breeding heat-tolerant varieties is an effective strategy to improve heat tolerance at the spring maize grain-filling stage [60]. Screening of various cultivars was done to screen the warmness of the plant canopy, stomata behavior of upper most leaf (flag leaf), and photosynthesizing efficiency that are closely related to each other for the production maximum grain production under high-temperature stress conditions [121–123].

### **3.6 Morpho-physiological mechanisms**

Under HT conditions, plants exhibit various mechanisms for surviving, which include long-term evolutionary phenological and morphological adaptations and short-term avoidance or acclimation mechanisms such as changing the leaf orientation, transpirational cooling, or alteration of membrane lipid compositions [92]. Also, high-temperature stress can be avoided by crop management practices such as selecting proper sowing methods, choice of sowing date, cultivars, irrigation methods, etc. It was discussed that combined hotter and drier climate change scenarios cause a greater maize yield reduction than hotter only scenarios. The incorporating drought and heat tolerance into maize germplasm has the potential to offset predicted yield losses and sustain maize productivity under climate change [19].

Tao and Zhao [60] reported that superoxide dismutase (SOD) increased and malonic dialdehyde (MDA) decreased in maize ear leaf for enhancing the stability of cell membrane, which helps to improve photosynthesis for good grain-filling characteristics (long quickly increase period and high mean rate of grain filling). It also produced high kernel weight under HTS [124, 125] leading to reporting of new origins of genetic engineering which exhibited leakage of electrolytes and MSI are the two basic parameters to screen the temperature stress-tolerant cultivars of various crops [126]. Electrical ions were gathered from the affected plants and were washed out with pure water to measure the membrane stability index MSI [127]. Seed production ability and stability index of the membrane were closely related to each other [3]. Mitochondrial tetrazolium is a very useful indicator of HTS sensitivity. Leaves' tissues were dipped in triphenyl tetrazolium chloride chemical mixture during HTS. The spectrographic technique was used to quantify the related rates of triphenyl tetrazolium chloride reduction to formazan and tissues viability [128]. Heat tolerance (HT) of the crop is generally defined as the ability of the plant to grow and produce an economic yield under HS. This is a highly specific trait, and closely related to the species, even different organs and tissues of the same plant, may vary significantly in this respect. Plants have evolved various mechanisms for thriving under higher prevailing temperatures. They include short-term avoidance/ acclimation mechanism or long-term evolutionary adaptations [92]. Many alternative traits related to heat resistance in *Zea mays* have been identified, including leaf kinetics, net photosynthesis rate (Pn), leaf anatomy at seedling stage [129] anther emergence [130], pollen grain viability [131], etc. However, the utility of those traits in stress breeding is not well established to date. Furthermore, most of the research focused on the heat stress on temperate maize, whereas only limited information is available on tropical maize [42].

One of the ways to deal with the adverse effects of heat stress may involve exploring some molecules that have the potential to protect the plants from the harmful effects of HT. In recent decades, exogenous application of protectants such as osmoprotectants, phytohormones, signaling molecules, trace elements, etc., have shown a beneficial effect on plants grown under HTS and these protectants have growth-promoting and antioxidant capacity [21, 92]. Exogenous applications of several phytohormones were found to be effective in mitigating heat stress in plants. Accumulation of osmolytes such as proline (Pro), glycine betaine (GB), and trehalose (Tre) is a well-known adaptive mechanism in plants against abiotic stress conditions including HT [92]. Supplementation with Pro and GB considerably reduced the H2O2 production, improved the accumulation of soluble sugars, and protected the developing tissues from heat stress effects. At the field level, managing or manipulating cultural practices, such as the timing and methods for sowing, irrigation management, and selection of cultivars and species, can also considerably decrease the adverse effects of HT stress. In recent decades, exogenous applications

**173**

*Maize Adaptability to Heat Stress under Changing Climate*

of protectants such as osmoprotectants, phytohormones, signaling molecules, trace elements, etc., have shown beneficial effects on plants growing under HT, due to the

The genetic analytical study depends upon the genetic markers. Information about genetic reproduction aids to identify potential gene markers [132]. To mitigate the harmful effects of high-temperature several gene markers like a random polymorphic amplifier, AFLP (amplifier fragmentation length polymorphism), as well as sequenced simple repeats SSR, were used to increase the crop production under heat-stress [133, 134]. During genetic breeding, the SNP marker was used because of its genetic sequence in legumes to identify resistant genotypes against heat stress [135]. QTL chromosome numbers and their origin were very useful to mitigate the effects of heat stress [132]. Different molecular markers are studied in population genomics across the environment in many individuals to find out novel variation patterns and help to find if the genes have functions in significant ecological traits. Genome-wide association study (GWAS) is a powerful tool for understanding the complete set of genetic variants in different crop cultivars to recognize allelic variant linked with any specific [136]. GWASs generally highlight linkage among SNPs single nucleotide polymorphism marker and traits and based on GWAS design, genotyping tools, statistical models for examination, and results

Heat stress disturbed the crop metabolic activities by changing tissue balance. Heat stress directly produced toxic substances in plant tissues call ROS due to which plant suffers from oxidative stress. Moreover, to reduce oxidative damage resulting from heat-induced oxidative stress, plants have developed different adaptive mechanisms, via the biosynthesis of enzymatic and non-enzymatic antioxidants and the sequestering of other materials in crop tissues. Enhancement of antioxidant defense system is an important strategy to scavenge ROS by antioxidant enzymes such as ascorbate peroxidase (APX), ascorbate reductase (AR), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPX), and superoxide dismutase (SOD) and with non-enzymatic antioxidants such as ascorbate (AsA), glutathione (GSH), carotenoids, flavanones, and anthocyanins [92]. Furthermore, adaptation to temperature changes, at the molecular level, was accompanied by the degradation of the normal proteins and the synthesis of HSPs involved in the mechanism of defense in plants. Seed germination is the most critical growth stage of the whole plant life cycle because it is the first step to carry out whole-plant growth and development, but heat stress is the main reducing factor of seedling emergence in

Heat stress and unprecedented climate changes have become a major challenge for sustainable crop production globally. Plant growth, development, and productivity get compromised due to heat stress. Elucidating maize hybrid for temperature tolerance could be an indispensable step toward a balanced yield. Tolerance and avoidance of stress could be an easy way to boost crop production under a changing climate; for example photosynthetic rate can be improved by targeting candidate

growth-promoting and antioxidant activities of these compounds [21, 92].

**3.8 Accumulation of antioxidants and heat-shock proteins**

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

**3.7 Molecular markers utilization**

in interpretation [137].

semiarid areas [138, 139].

**4. Conclusion**

of protectants such as osmoprotectants, phytohormones, signaling molecules, trace elements, etc., have shown beneficial effects on plants growing under HT, due to the growth-promoting and antioxidant activities of these compounds [21, 92].

### **3.7 Molecular markers utilization**

*Plant Stress Physiology*

**3.6 Morpho-physiological mechanisms**

Under HT conditions, plants exhibit various mechanisms for surviving, which include long-term evolutionary phenological and morphological adaptations and short-term avoidance or acclimation mechanisms such as changing the leaf orientation, transpirational cooling, or alteration of membrane lipid compositions [92]. Also, high-temperature stress can be avoided by crop management practices such as selecting proper sowing methods, choice of sowing date, cultivars, irrigation methods, etc. It was discussed that combined hotter and drier climate change scenarios cause a greater maize yield reduction than hotter only scenarios. The incorporating drought and heat tolerance into maize germplasm has the potential to offset predicted yield losses and sustain maize productivity under climate change [19]. Tao and Zhao [60] reported that superoxide dismutase (SOD) increased and malonic dialdehyde (MDA) decreased in maize ear leaf for enhancing the stability of cell membrane, which helps to improve photosynthesis for good grain-filling characteristics (long quickly increase period and high mean rate of grain filling). It also produced high kernel weight under HTS [124, 125] leading to reporting of new origins of genetic engineering which exhibited leakage of electrolytes and MSI are the two basic parameters to screen the temperature stress-tolerant cultivars of various crops [126]. Electrical ions were gathered from the affected plants and were washed out with pure water to measure the membrane stability index MSI [127]. Seed production ability and stability index of the membrane were closely related to each other [3]. Mitochondrial tetrazolium is a very useful indicator of HTS sensitivity. Leaves' tissues were dipped in triphenyl tetrazolium chloride chemical mixture during HTS. The spectrographic technique was used to quantify the related rates of triphenyl tetrazolium chloride reduction to formazan and tissues viability [128]. Heat tolerance (HT) of the crop is generally defined as the ability of the plant to grow and produce an economic yield under HS. This is a highly specific trait, and closely related to the species, even different organs and tissues of the same plant, may vary significantly in this respect. Plants have evolved various mechanisms for thriving under higher prevailing temperatures. They include short-term avoidance/ acclimation mechanism or long-term evolutionary adaptations [92]. Many alternative traits related to heat resistance in *Zea mays* have been identified, including leaf kinetics, net photosynthesis rate (Pn), leaf anatomy at seedling stage [129] anther emergence [130], pollen grain viability [131], etc. However, the utility of those traits in stress breeding is not well established to date. Furthermore, most of the research focused on the heat stress on temperate maize, whereas only limited information is

One of the ways to deal with the adverse effects of heat stress may involve exploring some molecules that have the potential to protect the plants from the harmful effects of HT. In recent decades, exogenous application of protectants such as osmoprotectants, phytohormones, signaling molecules, trace elements, etc., have shown a beneficial effect on plants grown under HTS and these protectants have growth-promoting and antioxidant capacity [21, 92]. Exogenous applications of several phytohormones were found to be effective in mitigating heat stress in plants. Accumulation of osmolytes such as proline (Pro), glycine betaine (GB), and trehalose (Tre) is a well-known adaptive mechanism in plants against abiotic stress conditions including HT [92]. Supplementation with Pro and GB considerably reduced the H2O2 production, improved the accumulation of soluble sugars, and protected the developing tissues from heat stress effects. At the field level, managing or manipulating cultural practices, such as the timing and methods for sowing, irrigation management, and selection of cultivars and species, can also considerably decrease the adverse effects of HT stress. In recent decades, exogenous applications

**172**

available on tropical maize [42].

The genetic analytical study depends upon the genetic markers. Information about genetic reproduction aids to identify potential gene markers [132]. To mitigate the harmful effects of high-temperature several gene markers like a random polymorphic amplifier, AFLP (amplifier fragmentation length polymorphism), as well as sequenced simple repeats SSR, were used to increase the crop production under heat-stress [133, 134]. During genetic breeding, the SNP marker was used because of its genetic sequence in legumes to identify resistant genotypes against heat stress [135]. QTL chromosome numbers and their origin were very useful to mitigate the effects of heat stress [132]. Different molecular markers are studied in population genomics across the environment in many individuals to find out novel variation patterns and help to find if the genes have functions in significant ecological traits. Genome-wide association study (GWAS) is a powerful tool for understanding the complete set of genetic variants in different crop cultivars to recognize allelic variant linked with any specific [136]. GWASs generally highlight linkage among SNPs single nucleotide polymorphism marker and traits and based on GWAS design, genotyping tools, statistical models for examination, and results in interpretation [137].

### **3.8 Accumulation of antioxidants and heat-shock proteins**

Heat stress disturbed the crop metabolic activities by changing tissue balance. Heat stress directly produced toxic substances in plant tissues call ROS due to which plant suffers from oxidative stress. Moreover, to reduce oxidative damage resulting from heat-induced oxidative stress, plants have developed different adaptive mechanisms, via the biosynthesis of enzymatic and non-enzymatic antioxidants and the sequestering of other materials in crop tissues. Enhancement of antioxidant defense system is an important strategy to scavenge ROS by antioxidant enzymes such as ascorbate peroxidase (APX), ascorbate reductase (AR), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPX), and superoxide dismutase (SOD) and with non-enzymatic antioxidants such as ascorbate (AsA), glutathione (GSH), carotenoids, flavanones, and anthocyanins [92]. Furthermore, adaptation to temperature changes, at the molecular level, was accompanied by the degradation of the normal proteins and the synthesis of HSPs involved in the mechanism of defense in plants. Seed germination is the most critical growth stage of the whole plant life cycle because it is the first step to carry out whole-plant growth and development, but heat stress is the main reducing factor of seedling emergence in semiarid areas [138, 139].

### **4. Conclusion**

Heat stress and unprecedented climate changes have become a major challenge for sustainable crop production globally. Plant growth, development, and productivity get compromised due to heat stress. Elucidating maize hybrid for temperature tolerance could be an indispensable step toward a balanced yield. Tolerance and avoidance of stress could be an easy way to boost crop production under a changing climate; for example photosynthetic rate can be improved by targeting candidate

traits and candidate genes involved in photosynthesis at a molecular level. It could lead to high assimilates production, more transportation of sugar to grain; finally, it decreases grain-filling rate, improves kernel size, and could be very useful to improve plant productivity. Heat-insensitive maize hybrids can be developed by gene editing *CRISPER-CAS9* system through targeting a gene that is responsible for heat sensitivity. The base of further research should be focused on spring maize crops. Field experiments regarding the sowing date are essential by analyzing the impact of meteorological factors on maize growth and grain yield. Application of osmoprotectants, nanotechnology, and the use of sustainable agriculture agents have become necessary for further research. Further, interdisciplinary studies that include agronomy, animal sciences, and climate modeling are warranted to assess the impact of the feeding of both the HTS-tolerant maize varieties and those grown under heat stress on animal health and production. This review could encourage such interdisciplinary approaches to develop maize hybrids with high nutritional values and are not prone to drastic yield reductions owing to fluctuations in agroclimatic factors (especially temperature) and the outcome may lead to sustainable maize production in the tropics under changing climate.

## **Conflicts of interest**

The authors declare no conflicts of interest.

## **Disclaimer**

We hereby declare that the book chapter does not have any material which has been accepted to publish any journal or publisher, and also has no copy of any material in previously published, except where due permission and reference is made in the text.

**175**

*Maize Adaptability to Heat Stress under Changing Climate*

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

**Author details**

Celaleddin Barutçular4

Kafr El-Sheikh, Egypt

Rawalakot (AJK), Pakistan

University, Bangladesh

Institute of Biology, Kyiv, Ukraine

provided the original work is properly cited.

Turkey

Ayman EL Sabagh1,6\*, Akbar Hossain2

Oksana Sytar7,8, Marian Brestic8

Muhammad Ikram16, Sobhy Sorour1

Liyun Liu23 and Hirofumi Saneoka23

\*, Muhammad Aamir Iqbal3

, Fatih Çiğ6

, Tasmiya Jabeen10,

, Wajid Nasim17, Mabrouk Elsabagh18,19,

, Mohammad Sohidul Islam<sup>5</sup>

Maham Asif Bukhari10, Muhammad Mubeen10, Habib-ur-Rehman Athar11, Faraz Azeem12, Hakki Akdeniz13, Ömer Konuşkan14, Ferhat Kizilgeci15,

, Allah Wasaya9

Muhammad Rizwan20, Ram Swaroop Meena21, Shah Fahad22, Akihiro Ueda23,

1 Faculty of Agriculture, Department of Agronomy, Kafrelsheikh University,

3 Faculty of Agriculture, Department of Agronomy, University of Poonch

4 Faculty of Agriculture, Department of Field Crops, Cukurova University, Adana,

5 Department of Agronomy, Hajee Mohammad Danesh Science and Technology

6 Faculty of Agriculture, Department of Field Crops, Siirt University, Turkey

7 Department of Plant Biology, Taras Shevchenko National University of Kyiv,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

2 Bangladesh Wheat and Maize Research Institute, Bangladesh

,

, Murat Erman6

,

## **Author details**

*Plant Stress Physiology*

**Conflicts of interest**

**Disclaimer**

the text.

traits and candidate genes involved in photosynthesis at a molecular level. It could lead to high assimilates production, more transportation of sugar to grain; finally, it decreases grain-filling rate, improves kernel size, and could be very useful to improve plant productivity. Heat-insensitive maize hybrids can be developed by gene editing *CRISPER-CAS9* system through targeting a gene that is responsible for heat sensitivity. The base of further research should be focused on spring maize crops. Field experiments regarding the sowing date are essential by analyzing the impact of meteorological factors on maize growth and grain yield. Application of osmoprotectants, nanotechnology, and the use of sustainable agriculture agents have become necessary for further research. Further, interdisciplinary studies that include agronomy, animal sciences, and climate modeling are warranted to assess the impact of the feeding of both the HTS-tolerant maize varieties and those grown under heat stress on animal health and production. This review could encourage such interdisciplinary approaches to develop maize hybrids with high nutritional values and are not prone to drastic yield reductions owing to fluctuations in agroclimatic factors (especially temperature) and the outcome may lead to sustainable

We hereby declare that the book chapter does not have any material which has been accepted to publish any journal or publisher, and also has no copy of any material in previously published, except where due permission and reference is made in

maize production in the tropics under changing climate.

The authors declare no conflicts of interest.

**174**

Ayman EL Sabagh1,6\*, Akbar Hossain2 \*, Muhammad Aamir Iqbal3 , Celaleddin Barutçular4 , Mohammad Sohidul Islam<sup>5</sup> , Fatih Çiğ6 , Murat Erman6 , Oksana Sytar7,8, Marian Brestic8 , Allah Wasaya9 , Tasmiya Jabeen10, Maham Asif Bukhari10, Muhammad Mubeen10, Habib-ur-Rehman Athar11, Faraz Azeem12, Hakki Akdeniz13, Ömer Konuşkan14, Ferhat Kizilgeci15, Muhammad Ikram16, Sobhy Sorour1 , Wajid Nasim17, Mabrouk Elsabagh18,19, Muhammad Rizwan20, Ram Swaroop Meena21, Shah Fahad22, Akihiro Ueda23, Liyun Liu23 and Hirofumi Saneoka23

1 Faculty of Agriculture, Department of Agronomy, Kafrelsheikh University, Kafr El-Sheikh, Egypt

2 Bangladesh Wheat and Maize Research Institute, Bangladesh

3 Faculty of Agriculture, Department of Agronomy, University of Poonch Rawalakot (AJK), Pakistan

4 Faculty of Agriculture, Department of Field Crops, Cukurova University, Adana, Turkey

5 Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Bangladesh

6 Faculty of Agriculture, Department of Field Crops, Siirt University, Turkey

7 Department of Plant Biology, Taras Shevchenko National University of Kyiv, Institute of Biology, Kyiv, Ukraine

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

8 Department of Plant Physiology, Slovak University of Agriculture, Nitra, Slovak Republic

9 College of Agriculture, BZU, Bahadur Sub-Campus Layyah, Pakistan

10 Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus, Pakistan

11 Botany Department, Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan, Pakistan

12 National Institute of Plant Genome Research, New Delhi, India

13 Igdir Universitesi, Ziraat Fakultesi, Tarla Bitkileri Bölümü, Igdir, Turkey

14 Faculty of Agriculture, Department of Field Crops, Mustafa Kemal University, Hatay, Turkey

15 Kiziltepe Vocational School, Mardin Artuklu University, Mardin, Turkey

16 Faculty of Agricultural Sciences and Technology, Department of Agronomy, Bahauddin Zakariya University, Multan, Pakistan

17 Department of Agronomy, University College of Agriculture and Environmental Sciences, The Islamia University of Bahawalpur (IUB), Bahawalpur, Pakistan

18 Faculty of Agricultural Sciences and Technologies, Department of Animal Production and Technology, Niğde Ömer Halisdemir University, Niğde, Turkey

19 Faculty of Veterinary Medicine, Department of Nutrition and Clinical Nutrition, Kafrelsheikh University, Kafr El-Sheikh, Egypt

20 Department of Agronomy, PMAS-Arid Agriculture University, Rawalpindi, Pakistan

21 Department of Agronomy, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, UP, India

22 Agriculture Department, The University of Swabi, Pakistan

23 Laboratory of Plant Nutritional Physiology, Graduate School of Biosphere Science, Hiroshima University, Japan

\*Address all correspondence to: aymanelsabagh@gmail.com and akbarhossainwrc@gmail.com

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**177**

*Maize Adaptability to Heat Stress under Changing Climate*

[8] Abdelaal KA, Hafez YM, El Sabagh A, Saneoka H. Ameliorative effects of abscisic acid and yeast on morpho-physiological and yield characteristics of maize plant (*Zea mays* L.) under water deficit conditions. Fresenius Environmental Bulletin.

[9] Majid MA, Islam MS, EL Sabagh A, Hasan MK, Saddam MO, Barutcular C, et al. Influence of varying nitrogen levels on growth, yield and nitrogen use efficiency of hybrid maize (*Zea mays* L.). Journal of Experimental Biology and Agricultural Sciences.

2017;**26**(12):7372-7383

2017;**5**(2):134-142

[10] El Sabagh A, Hossain A, Barutçular C, Abdelaal K, Fahad S, Anjorin F, et al. Sustainable maize (*Zea mays* L.) production under drought stress by understanding its adverse effect, survival mechanism and drought tolerance indices. Journal of Experimental Biology and Agricultural

Sciences. 2018;**6**(2):282-295

2018;**27**(4):2476-2482

[12] Ignjatovic-Micic D, Kostadinovic M, Bozinovic S,

[13] Ranum P, Pena-Rosas JP, Garcia-Casal MN. Global maize production, utilization, and consumption. Annals of the New York Academy of Sciences.

[14] Barutçular C, El Sabagh A, Konuskan O, Saneoka H,

2014;**1312**(1):105-112

Andjelkovic V, Vancetovic J. High grain quality accessions within a maize drought-tolerant core collection. Scientia Agricola. 2014;**71**:345-355

[11] El Sabagh A, Barutçular C, Hossain A, Islam MS. Response of maize hybrids to drought tolerance indices in relation to grain weight. Fresenius Environmental Bulletin.

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

[1] Farooq M, Bramley H, Palta JA, Siddique KHM. Heat stress in wheat during reproductive and grain-filling phases. Critical Reviews in Plant Sciences. 2011;**30**(6):491-507

[2] Molla MSH, Nakasathien S, Ali MA, Khan ASMMR, Alam MR, Hossain A, et al. Influence of nitrogen application on dry biomass allocation and translocation in two maize varieties under short pre-anthesis and prolonged bracketing flowering

periods of drought. Archives of Agronomy and Soil Science.

[3] Rojas-Downing MM, Nejadhashemi AP, Harrigan T, Woznicki SA. Climate change and livestock: Impacts, adaptation, and mitigation. Climate Risk Management. 2017;**16**:145-163

[4] Vogel E, Donat MG, Alexander LV, Meinshausen M, Ray DK, Karoly DG, et al. The effects of climate extremes

[5] Shiferaw B, Prasanna BM, Hellin J, Bänziger M. Crops that feed the world: Past successes and future challenges to the role played by maize in global food security. Food Security. 2011;**3**:307-311

[6] Khaliq A, Iqbal MA, Zafar M, Gulzar A. Appraising economic dimension of maize production under coherent fertilization in Azad Kashmir, Pakistan. Custos e Agronegocio.

[7] El Sabagh A, Barutcular C, Islam MS.

Relationships between stomatal conductance and yield under deficit irrigation in maize (*Zea mays* L.). Journal of Experimental Biology and Agricultural Sciences. 2017;**5**:15-21. DOI: 10.18006/2017.5 (1).014.021

**2019**;**15**(2):243-253

on global agricultural yields. Environmental Research Letters. 2019;**14**(5). DOI: 10.1088/1748-9326/

ab154b

2019;**65**(7):928-944

**References**

*Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

### **References**

*Plant Stress Physiology*

Slovak Republic

Campus, Pakistan

Hatay, Turkey

Pakistan

University, Multan, Pakistan

8 Department of Plant Physiology, Slovak University of Agriculture, Nitra,

10 Department of Environmental Sciences, COMSATS University Islamabad, Vehari

11 Botany Department, Institute of Pure and Applied Biology, Bahauddin Zakariya

9 College of Agriculture, BZU, Bahadur Sub-Campus Layyah, Pakistan

12 National Institute of Plant Genome Research, New Delhi, India

Bahauddin Zakariya University, Multan, Pakistan

Kafrelsheikh University, Kafr El-Sheikh, Egypt

University, Varanasi, UP, India

Science, Hiroshima University, Japan

and akbarhossainwrc@gmail.com

provided the original work is properly cited.

13 Igdir Universitesi, Ziraat Fakultesi, Tarla Bitkileri Bölümü, Igdir, Turkey

15 Kiziltepe Vocational School, Mardin Artuklu University, Mardin, Turkey

16 Faculty of Agricultural Sciences and Technology, Department of Agronomy,

18 Faculty of Agricultural Sciences and Technologies, Department of Animal Production and Technology, Niğde Ömer Halisdemir University, Niğde, Turkey

20 Department of Agronomy, PMAS-Arid Agriculture University, Rawalpindi,

21 Department of Agronomy, Institute of Agricultural Sciences, Banaras Hindu

23 Laboratory of Plant Nutritional Physiology, Graduate School of Biosphere

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

22 Agriculture Department, The University of Swabi, Pakistan

\*Address all correspondence to: aymanelsabagh@gmail.com

17 Department of Agronomy, University College of Agriculture and Environmental Sciences, The Islamia University of Bahawalpur (IUB), Bahawalpur, Pakistan

19 Faculty of Veterinary Medicine, Department of Nutrition and Clinical Nutrition,

14 Faculty of Agriculture, Department of Field Crops, Mustafa Kemal University,

**176**

[1] Farooq M, Bramley H, Palta JA, Siddique KHM. Heat stress in wheat during reproductive and grain-filling phases. Critical Reviews in Plant Sciences. 2011;**30**(6):491-507

[2] Molla MSH, Nakasathien S, Ali MA, Khan ASMMR, Alam MR, Hossain A, et al. Influence of nitrogen application on dry biomass allocation and translocation in two maize varieties under short pre-anthesis and prolonged bracketing flowering periods of drought. Archives of Agronomy and Soil Science. 2019;**65**(7):928-944

[3] Rojas-Downing MM, Nejadhashemi AP, Harrigan T, Woznicki SA. Climate change and livestock: Impacts, adaptation, and mitigation. Climate Risk Management. 2017;**16**:145-163

[4] Vogel E, Donat MG, Alexander LV, Meinshausen M, Ray DK, Karoly DG, et al. The effects of climate extremes on global agricultural yields. Environmental Research Letters. 2019;**14**(5). DOI: 10.1088/1748-9326/ ab154b

[5] Shiferaw B, Prasanna BM, Hellin J, Bänziger M. Crops that feed the world: Past successes and future challenges to the role played by maize in global food security. Food Security. 2011;**3**:307-311

[6] Khaliq A, Iqbal MA, Zafar M, Gulzar A. Appraising economic dimension of maize production under coherent fertilization in Azad Kashmir, Pakistan. Custos e Agronegocio. **2019**;**15**(2):243-253

[7] El Sabagh A, Barutcular C, Islam MS. Relationships between stomatal conductance and yield under deficit irrigation in maize (*Zea mays* L.). Journal of Experimental Biology and Agricultural Sciences. 2017;**5**:15-21. DOI: 10.18006/2017.5 (1).014.021

[8] Abdelaal KA, Hafez YM, El Sabagh A, Saneoka H. Ameliorative effects of abscisic acid and yeast on morpho-physiological and yield characteristics of maize plant (*Zea mays* L.) under water deficit conditions. Fresenius Environmental Bulletin. 2017;**26**(12):7372-7383

[9] Majid MA, Islam MS, EL Sabagh A, Hasan MK, Saddam MO, Barutcular C, et al. Influence of varying nitrogen levels on growth, yield and nitrogen use efficiency of hybrid maize (*Zea mays* L.). Journal of Experimental Biology and Agricultural Sciences. 2017;**5**(2):134-142

[10] El Sabagh A, Hossain A, Barutçular C, Abdelaal K, Fahad S, Anjorin F, et al. Sustainable maize (*Zea mays* L.) production under drought stress by understanding its adverse effect, survival mechanism and drought tolerance indices. Journal of Experimental Biology and Agricultural Sciences. 2018;**6**(2):282-295

[11] El Sabagh A, Barutçular C, Hossain A, Islam MS. Response of maize hybrids to drought tolerance indices in relation to grain weight. Fresenius Environmental Bulletin. 2018;**27**(4):2476-2482

[12] Ignjatovic-Micic D, Kostadinovic M, Bozinovic S, Andjelkovic V, Vancetovic J. High grain quality accessions within a maize drought-tolerant core collection. Scientia Agricola. 2014;**71**:345-355

[13] Ranum P, Pena-Rosas JP, Garcia-Casal MN. Global maize production, utilization, and consumption. Annals of the New York Academy of Sciences. 2014;**1312**(1):105-112

[14] Barutçular C, El Sabagh A, Konuskan O, Saneoka H,

Yoldash KM. Evaluation of maize hybrids to terminal drought stress tolerance by defining drought indices. Journal of Experimental Biology and Agricultural Sciences. 2016;**4**(6):610-616

[15] Barutçular C, Yıldırım M, Koç M, Akıncı C, Toptaş I, Albayrak O, et al. Evaluation of SPAD chlorophyll in spring wheat genotypes under different environments. Fresenius Environmental Bulletin. 2016;**25**(4):1258-1266

[16] Cairns JE, Sonder K, Zaidi PH, Verhulst N, Mahuku G, Babu R. Maize production in a changing climate. Advances in Agronomy. 2012;**144**:1-58

[17] Iqbal A, Iqbal MA, Iqbal A, Zubair A, Muhammad M, Zahoor A, et al. Boosting forage yield and quality of maize (*Zea mays* L.) with multispecies bacterial inoculation in Pakistan. Phyton International Journal of Experimental Botany. 2017;**86**:84-88

[18] Zhao F, Zhang D, Zhao Y, Wang W, Yang H, Tai F, et al. The difference of physiological and proteomic changes in maize leaves adaptation to drought, heat, and combined both stresses. Frontiers in Plant Science. 2016;**7**:1471. DOI: 10.3389/fpls.2016.01471

[19] Cairns JE, Hellin J, Sonder AJL, MacRobert JF, Thierfelder C, Prasanna BM. Adapting maize production to climate change in sub-Saharan Africa. Food Security. 2013;**5**:345. DOI: 10.1007/ s12571-013-0256-x

[20] Meena H, Meena RS, Rajput BS, Kumar S. Response of bio-regulators to morphology and yield of clusterbean [*Cyamopsis tetragonoloba* (L.) Taub.] under different sowing environments. Journal of Applied and Natural Science. 2016;**8**:715-718

[21] Hasanuzzaman M, Gill SS, Fujita M. Physiological role of nitric oxide in plants grown under adverse environmental conditions. In: Gill SS, Tuteja N, editors. Plant Acclimation to Environmental Stress. New York: Springer; 2013. pp. 269-322

[22] Bahar B, Yildirim M, Barutçular C. Relationships between stomatal conductance and yield components in spring durum wheat under Mediterranean conditions. Notulae Botanicae Horti Agrobotanici Cluj-Napoca. 2009;**37**:45-48. DOI: 10.15835/ nbha3723084

[23] Barutçular C, Yildirim M, Koç M, Akinci C, Tanrikulu A, El-Sabagh A, et al. Quality traits performance of bread wheat genotypes under drought and heat stress conditions. Fresenius Environmental Bulletin. 2016;**25**(10):1-7

[24] Jiang Q, Roche D, Monaco TA, Hole D. Stomatal conductance is a key parameter to assess limitations to photosynthesis and growth potential in barley genotypes. Plant Biology. 2006;**8**:515-521. DOI: 10.1055/s-2006-923964

[25] Blum A. Crop responses to drought and the interpretation to adaptation. Plant Growth Regulation. 1996;**20**:135-148

[26] Khalili M, Moghaddam M, Kazemi Arbat H, Shakiba MR, Kanooni H, Choukan R. Effect of drought stress on different corn genotypes. Journal of Agricultural Science. 2010;**2**(20):67-84

[27] Yassin M, Mekawy AM, El Sabagh A, Islam MS, Hossain A, Barutcular C, et al. Physiological and biochemical responses of two bread wheat (*Triticum aestivum* L.) genotypes grown under salinity stress. Applied Ecology and Environmental Research. 2019;**17**(2):5029-5041

[28] Kumar S, Meena RS, Bohra JS. Interactive effect of sowing dates and nutrient sources on dry matter

**179**

*Maize Adaptability to Heat Stress under Changing Climate*

[36] Schoffl F, Prandl R, Reindl A. Molecular responses to heat stress. In: Shinozaki K, Yamaguchi-Shinozaki K, editors. Molecular Responses to Cold, Drought, Heat and Salt Stress in Higher Plants. Austin, Texas: R.G. Landes Co.;

[37] Howarth CJ. Genetic improvements of tolerance to high temperature. In: Ashraf M, Harris PJC, editors. Abiotic Stresses Plant Resistance Through Breeding and Molecular Approaches. New York: Howarth Press Inc.; 2005

[38] Lindquist S, Craig EA. The heatshock proteins. Annual Review of

[39] Vierling E. The roles of heat shock proteins in plants. Annual Review of Plant Physiology and Plant Molecular

[40] Mariamma M, Muthukumar B, Veluthambi K, Gnanam A. Effects of high temperature stress on the expression of low molecular weight heat shock proteins in rice leaves. Journal of Plant Physiology.

[41] Perras M, Sarhan F. Synthesis of freezing tolerance proteins in leaves, crown and roots during cold acclimation of wheat. Plant Physiology.

[42] Monjardino P, Smith AG,

Science. 1991;**31**:1579-1583

[44] Noor JJ, Vinayan MT, Umar S, Devi P, Iqbal M, Seetharam K, et al. Morpho-physiological traits associated with heat stress tolerance in tropical maize (*Zea mays* L.) at reproductive

Jones RJ. Heat stress effects on protein accumulation of maize endosperm. Crop Science. 2005;**45**:1203-1210

[43] Duthion C, Pigesire A. Seed length corresponding to the final stage seed abortion of three grain legumes. Crop

Genetics. 1988;**22**:631-677

Biology. 1991;**42**:579-620

1997;**151**:763-765

1989;**89**:577-585

1999. pp. 81-98

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

accumulation of Indian mustard (*Brassica juncea* L.). Journal of Oilseed

[29] Monneveux P, Sanchez C,

tolerance in maize needs new secondary traits and cross

[30] Barutcular C, El Sabagh A, Koc M, Ratnasekera D. Relationships between grain yield and physiological traits of durum wheat varieties under drought and high temperature stress in Mediterranean environments. Fresenius Environmental Bulletin.

2017;**26**:4282-4291

[31] Havaux M. Carotenoids as membrane stabilizers in

S1360-1385(98)01200-X

of plants' tolerance to high

fpls.2017.00953

chloroplasts. Trends in Plant Science. 1998;**3**(4):147-151. DOI: 10.1016/

[32] Yildiz M, Terzi H. Determination

temperature stress by cell viability and photosynthetic pigmentation tests. Erciyes UFBE Der. 2007;**23**(1-2):47-60

[33] Zandalinas SI, Balfagón D, Arbona V, Gómez-Cadenas A. Modulation of antioxidant defense system is associated with combined drought and heat stress tolerance in citrus. Frontiers in Plant Science. 2017;**8**:953. DOI: 10.3389/

[34] Soengas P, Rodríguez VM, Velasco P, Cartea ME. Effect of temperature stress on antioxidant defenses in *Brassica oleracea*. ACS Omega. 2018;**3**(5):5237- 5243. DOI: 10.1021/acsomega.8b00242

[35] Thirunavukkarasu N, Sharma R, Singh N. Genome wide expression and functional interactions of genes under drought stress in maize. International Journal of Genomics. 2017;**2568706**.

DOI: 10.1155/2017/2568706

Tiessen A. Future progress in drought

combinations. Journal of Agricultural Science. 2008;**146**:287-300. DOI: 10.1017/S0021859608007818 P

Brassica. 2018;**9**(1):72-76

*Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

accumulation of Indian mustard (*Brassica juncea* L.). Journal of Oilseed Brassica. 2018;**9**(1):72-76

*Plant Stress Physiology*

2016;**4**(6):610-616

Yoldash KM. Evaluation of maize hybrids to terminal drought stress tolerance by defining drought indices. Journal of Experimental Biology and Agricultural Sciences. oxide in plants grown under adverse environmental conditions. In: Gill SS, Tuteja N, editors. Plant Acclimation to Environmental Stress. New York:

[22] Bahar B, Yildirim M, Barutçular C. Relationships between stomatal conductance and yield components in spring durum wheat under Mediterranean conditions. Notulae Botanicae Horti Agrobotanici Cluj-Napoca. 2009;**37**:45-48. DOI: 10.15835/

[23] Barutçular C, Yildirim M, Koç M, Akinci C, Tanrikulu A, El-Sabagh A, et al. Quality traits performance of bread wheat genotypes under drought and heat stress conditions. Fresenius Environmental Bulletin. 2016;**25**(10):1-7

[24] Jiang Q, Roche D, Monaco TA, Hole D. Stomatal conductance is a key parameter to assess limitations to photosynthesis and growth potential

in barley genotypes. Plant Biology. 2006;**8**:515-521. DOI: 10.1055/s-2006-923964

1996;**20**:135-148

[25] Blum A. Crop responses to drought and the interpretation to adaptation. Plant Growth Regulation.

[27] Yassin M, Mekawy AM, El Sabagh A, Islam MS, Hossain A, Barutcular C, et al. Physiological and biochemical responses of two bread wheat (*Triticum aestivum* L.) genotypes grown under salinity stress. Applied Ecology and Environmental Research.

[28] Kumar S, Meena RS, Bohra JS. Interactive effect of sowing dates and nutrient sources on dry matter

2019;**17**(2):5029-5041

[26] Khalili M, Moghaddam M, Kazemi Arbat H, Shakiba MR, Kanooni H, Choukan R. Effect of drought stress on different corn genotypes. Journal of Agricultural Science. 2010;**2**(20):67-84

Springer; 2013. pp. 269-322

nbha3723084

[15] Barutçular C, Yıldırım M, Koç M, Akıncı C, Toptaş I, Albayrak O, et al. Evaluation of SPAD chlorophyll in spring wheat genotypes under different environments. Fresenius Environmental

Bulletin. 2016;**25**(4):1258-1266

[17] Iqbal A, Iqbal MA, Iqbal A, Zubair A, Muhammad M, Zahoor A, et al. Boosting forage yield and quality of maize (*Zea mays* L.) with multispecies bacterial inoculation in Pakistan.

Phyton International Journal of Experimental Botany. 2017;**86**:84-88

DOI: 10.3389/fpls.2016.01471

s12571-013-0256-x

2016;**8**:715-718

[19] Cairns JE, Hellin J, Sonder AJL, MacRobert JF, Thierfelder C, Prasanna BM. Adapting maize production to climate change in sub-Saharan Africa. Food Security. 2013;**5**:345. DOI: 10.1007/

[20] Meena H, Meena RS, Rajput BS, Kumar S. Response of bio-regulators to morphology and yield of clusterbean [*Cyamopsis tetragonoloba* (L.) Taub.] under different sowing environments. Journal of Applied and Natural Science.

[21] Hasanuzzaman M, Gill SS, Fujita M. Physiological role of nitric

[18] Zhao F, Zhang D, Zhao Y, Wang W, Yang H, Tai F, et al. The difference of physiological and proteomic changes in maize leaves adaptation to drought, heat, and combined both stresses. Frontiers in Plant Science. 2016;**7**:1471.

[16] Cairns JE, Sonder K, Zaidi PH, Verhulst N, Mahuku G, Babu R. Maize production in a changing climate. Advances in Agronomy. 2012;**144**:1-58

**178**

[29] Monneveux P, Sanchez C, Tiessen A. Future progress in drought tolerance in maize needs new secondary traits and cross combinations. Journal of Agricultural Science. 2008;**146**:287-300. DOI: 10.1017/S0021859608007818 P

[30] Barutcular C, El Sabagh A, Koc M, Ratnasekera D. Relationships between grain yield and physiological traits of durum wheat varieties under drought and high temperature stress in Mediterranean environments. Fresenius Environmental Bulletin. 2017;**26**:4282-4291

[31] Havaux M. Carotenoids as membrane stabilizers in chloroplasts. Trends in Plant Science. 1998;**3**(4):147-151. DOI: 10.1016/ S1360-1385(98)01200-X

[32] Yildiz M, Terzi H. Determination of plants' tolerance to high temperature stress by cell viability and photosynthetic pigmentation tests. Erciyes UFBE Der. 2007;**23**(1-2):47-60

[33] Zandalinas SI, Balfagón D, Arbona V, Gómez-Cadenas A. Modulation of antioxidant defense system is associated with combined drought and heat stress tolerance in citrus. Frontiers in Plant Science. 2017;**8**:953. DOI: 10.3389/ fpls.2017.00953

[34] Soengas P, Rodríguez VM, Velasco P, Cartea ME. Effect of temperature stress on antioxidant defenses in *Brassica oleracea*. ACS Omega. 2018;**3**(5):5237- 5243. DOI: 10.1021/acsomega.8b00242

[35] Thirunavukkarasu N, Sharma R, Singh N. Genome wide expression and functional interactions of genes under drought stress in maize. International Journal of Genomics. 2017;**2568706**. DOI: 10.1155/2017/2568706

[36] Schoffl F, Prandl R, Reindl A. Molecular responses to heat stress. In: Shinozaki K, Yamaguchi-Shinozaki K, editors. Molecular Responses to Cold, Drought, Heat and Salt Stress in Higher Plants. Austin, Texas: R.G. Landes Co.; 1999. pp. 81-98

[37] Howarth CJ. Genetic improvements of tolerance to high temperature. In: Ashraf M, Harris PJC, editors. Abiotic Stresses Plant Resistance Through Breeding and Molecular Approaches. New York: Howarth Press Inc.; 2005

[38] Lindquist S, Craig EA. The heatshock proteins. Annual Review of Genetics. 1988;**22**:631-677

[39] Vierling E. The roles of heat shock proteins in plants. Annual Review of Plant Physiology and Plant Molecular Biology. 1991;**42**:579-620

[40] Mariamma M, Muthukumar B, Veluthambi K, Gnanam A. Effects of high temperature stress on the expression of low molecular weight heat shock proteins in rice leaves. Journal of Plant Physiology. 1997;**151**:763-765

[41] Perras M, Sarhan F. Synthesis of freezing tolerance proteins in leaves, crown and roots during cold acclimation of wheat. Plant Physiology. 1989;**89**:577-585

[42] Monjardino P, Smith AG, Jones RJ. Heat stress effects on protein accumulation of maize endosperm. Crop Science. 2005;**45**:1203-1210

[43] Duthion C, Pigesire A. Seed length corresponding to the final stage seed abortion of three grain legumes. Crop Science. 1991;**31**:1579-1583

[44] Noor JJ, Vinayan MT, Umar S, Devi P, Iqbal M, Seetharam K, et al. Morpho-physiological traits associated with heat stress tolerance in tropical maize (*Zea mays* L.) at reproductive

stage. Australian Journal of Crop Science. 2019;**13**(04):536-545

[45] Sehgal A, Sita K, Siddique KHM, Kumar R, Bhogireddy S, Varshney RK, et al. Drought or/and heat-stress effects on seed filling in food crops: Impacts on functional biochemistry, seed yields, and nutritional quality. Frontiers in Plant Science. 2018;**9**:1705. DOI: 10.3389/fpls.2018.01705

[46] Farooq M, Wahid A, Kobayashi N, Fujita D, Basra SMA. Plant drought stress: Effects, mechanisms and management. Agronomy for Sustainable Development. 2009;**29**:185-212

[47] Wahid A, Gelani S, Ashraf M, Foolad M. Heat tolerance in plants: An overview. Environmental and Experimental Botany. 2007;**61**:199-223. DOI: 10.1016/j.envexpbot.2007.05.011

[48] Borlu HO, Celiktas V, Duzenli S, Hossain A, El Sabagh A. Germination and early seedling growth of five durum wheat cultivars (*Triticum durum* desf.) is affected by different levels of salinity. Fresenius Environmental Bulletin. 2018;**27**(11):7746-7757

[49] Begcy K, Sandhu J, Walia H. Transient heat stress during early seed development primes germination and seedling establishment in rice. Frontiers in Plant Science. 2018;**9**:17-68. DOI: 10.3389/fpls.2018.01768

[50] Li R, Zeng Y, Xu J, Wang Q, Wu F, Cao M, et al. Genetic variation for maize root architecture in response to drought stress at the seedling stage. Breeding Science. 2015;**65**(4):298-307. DOI: 10.1270/jsbbs.65.298

[51] Anjum SA, Wang LC, Farooq M, Hussain M, Xue LL, Zou CM. Brassinolide application improves the drought tolerance in maize through modulation of enzymatic antioxidants and leaf gas exchange. Journal of Agronomy and Crop Science.

2011;**197**(3):177-185. DOI: 10.1111/j.1439 037X.2010.00459.x

[52] Shao HB, Chu LY, Shao MA, Jaleel CA, Hong-Mei M. Higher plant antioxidants and redox signaling under environmental stresses. Comptes Rendus Biologies. 2008;**331**(6):433-441

[53] Zivcak M, Brestic M, Sytar O. Osmotic adjustment and plant adaptation to drought stress. In: Hossain M, Wani S, Bhattacharjee S, Burritt D, Tran LS, editors. Drought Stress Tolerance in Plants. Vol. 1. Cham: Springer; 2016

[54] Buriro M, Oad FC, Keerio MI, Tunio S, Gandahi AW, Ul Hassan SW, et al. Wheat seed germination under the influence of temperature regimes. Sarhad Journal of Agriculture. 2011;**27**(4):539-543

[55] Anjorin FB, Adejumo SA, Agboola L, Samuel YD. Proline, soluble sugar, leaf starch and relative water contents of four maize varıetıes ın response to dıfferent watering regimes. Cercetri Agronomice în Moldova. 2016;**49**(3):51-62

[56] Bewley JD, Black M. Seeds: Physiology of Development and Germination. Vol. 2. Berlin: Springer-Verlag; 1986. pp. 297-304

[57] Joshi AK, Mishra B, Chatrath R, Ferrara GO, Singh RP. Wheat improvement in India: Present status, emerging challenges and future prospects. Euphytica. 2007;**157**(3):431-446

[58] Essemine J, Ammar S, Bouzid S. Impact of heat stress on germination and growth in higher plants: Physiological, biochemical and molecular repercussions and mechanisms of defence. Journal of Biological Sciences. 2010;**10**(6):565-572

**181**

*Maize Adaptability to Heat Stress under Changing Climate*

productivity. In: Amanullah K, Fahad S, editors. Corn: Production and Human Health in Changing Climate. 2018. p. 95.

DOI: 10.5772/intechopen.76933

[68] Edreira JI, Mayer LI, Otegui ME. Heat stress in temperate and tropical maize hybrids: Kernel growth, water relations and assimilate availability for grain filling. Field Crops Research.

[69] Rahman HU. Genetic analysis of stomatal conductance in upland cotton *(Gossypium hirsutum* L.*)* under contrasting temperature regimes. Journal of Agriculture Science.

[70] Talwar HS, Takeda H, Yashima S, Senboku T. Growth and photosynthetic responses of groundnut genotypes to high temperature. Crop Science. 1999;**39**:60-466. DOI: 10.2135/cropsci19

[71] Ristic Z, Momčilović I, Bukovnik U, Prasad PV, Fu J, DeRidder BP, et al. Rubisco activase and wheat productivity

99.0011183X0039000200027x

under heat-stress conditions. Journal of Experimental Botany.

[72] Hussain HA, Men S, Hussain S, Chen Y, Ali S, Zhang S, et al. Interactive effects of drought and heat stresses on morpho-physiological attributes, yield, nutrient uptake and oxidative status in maize hybrids. Scientific Reports. 2019;**9**:3890. DOI: 10.1038/

[73] Brdar MD, Kraljevíc-Balalíc MM, Kobiljski BD. The parameters of grain filling and yield components in common wheat (*Triticum aestivum* L.) and

2009;**60**(14):4003-4014

s41598-019-40362-7

[67] Alam A, Seetharam K, Zaidi PH, Dinesh A, Vinayan MT, Kumar NU. Dissecting heat stress tolerance in tropical maize (*Zea mays* L.). Field Crops Research.

2017;**204**:110-119

2014;**166**:162-172

2005;**143**:161-168

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

[59] Nejad SMH, Alizadeh O, Amiri B, Barzegari M, Bayat ME. The effects of drought and heat stress on some physiological and agronomic characteristics of new hybrids of corn in the north of Khuzestan Province (Iran). EurAsian Journal of BioSciences.

[60] Tao F, Zhao Z. Adaptation of maize production to climate change in North China Plain: Quantify the relative contributions of adaptation options. European Journal of Agronomy.

[61] Muchow RC. Effect of high temperature on grain-growth in fieldgrown maize. Field Crops Research.

[62] Singletary GW, Banisadr R, Keeling PL. Heat stress during grain filling in maize, effects on carbohydrate storage and metabolism. Australian

Journal of Plant Physiology.

[63] Suwa R, Hakata H, Hara H, El-Shemy HA, Adu-Gyamfi JJ, Nguyen NT, et al. High temperature effects on photosynthate partitioning and sugar metabolism during ear expansion in maize (*Zea mays* L.) genotypes. Plant Physiology and Biochemistry. 2010;**48**:124-130. DOI:

2017;**11**:32-36

2010;**33**:103-116

1990;**23**:145-158

1994;**21**:829-841

10.1071/PP9910259

10.1111/gcb.12069

[64] Hawkins E, Fricker TE, Challinor AJ, Ferro CA, Ho CK, Osborne TM. Increasing influence of heat stress on French maize yields from the 1960s to the 2030s. Global Change Biology. 2013;**19**(3):937-947. DOI:

[65] Harrison L, Michaelsen J, Funk C, Husak G. Effects of temperature changes on maize production in Mozambique. Climate Research. 2011;**46**(3):211-222

[66] Hatfield JL, Dold C. Climate change impacts on corn phenology and *Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

[59] Nejad SMH, Alizadeh O, Amiri B, Barzegari M, Bayat ME. The effects of drought and heat stress on some physiological and agronomic characteristics of new hybrids of corn in the north of Khuzestan Province (Iran). EurAsian Journal of BioSciences. 2017;**11**:32-36

*Plant Stress Physiology*

10.3389/fpls.2018.01705

stage. Australian Journal of Crop Science. 2019;**13**(04):536-545

[45] Sehgal A, Sita K, Siddique KHM, Kumar R, Bhogireddy S, Varshney RK, et al. Drought or/and heat-stress effects on seed filling in food crops: Impacts on functional biochemistry, seed yields, and nutritional quality. Frontiers in Plant Science. 2018;**9**:1705. DOI:

2011;**197**(3):177-185. DOI: 10.1111/j.1439

[52] Shao HB, Chu LY, Shao MA, Jaleel CA, Hong-Mei M. Higher plant antioxidants and redox signaling under environmental stresses. Comptes Rendus Biologies. 2008;**331**(6):433-441

[53] Zivcak M, Brestic M, Sytar O. Osmotic adjustment and plant adaptation to drought stress. In: Hossain M, Wani S, Bhattacharjee S, Burritt D, Tran LS, editors. Drought Stress Tolerance in Plants. Vol. 1. Cham:

[54] Buriro M, Oad FC, Keerio MI, Tunio S, Gandahi AW, Ul Hassan SW, et al. Wheat seed germination under the influence of temperature regimes. Sarhad Journal of Agriculture.

[55] Anjorin FB, Adejumo SA,

[56] Bewley JD, Black M. Seeds: Physiology of Development and Germination. Vol. 2. Berlin: Springer-

[57] Joshi AK, Mishra B, Chatrath R, Ferrara GO, Singh RP. Wheat improvement in India: Present status, emerging challenges and future prospects. Euphytica.

Verlag; 1986. pp. 297-304

2007;**157**(3):431-446

2010;**10**(6):565-572

[58] Essemine J, Ammar S,

Bouzid S. Impact of heat stress on germination and growth in higher plants: Physiological, biochemical and molecular repercussions and mechanisms of defence. Journal of Biological Sciences.

Agboola L, Samuel YD. Proline, soluble sugar, leaf starch and relative water contents of four maize varıetıes ın response to dıfferent watering regimes. Cercetri Agronomice în Moldova.

037X.2010.00459.x

Springer; 2016

2011;**27**(4):539-543

2016;**49**(3):51-62

[46] Farooq M, Wahid A, Kobayashi N, Fujita D, Basra SMA. Plant drought stress: Effects, mechanisms and

management. Agronomy for Sustainable

Development. 2009;**29**:185-212

[47] Wahid A, Gelani S, Ashraf M, Foolad M. Heat tolerance in plants: An overview. Environmental and Experimental Botany. 2007;**61**:199-223. DOI: 10.1016/j.envexpbot.2007.05.011

[48] Borlu HO, Celiktas V, Duzenli S, Hossain A, El Sabagh A. Germination and early seedling growth of five durum wheat cultivars (*Triticum durum* desf.) is affected by different levels of salinity. Fresenius Environmental Bulletin.

2018;**27**(11):7746-7757

10.3389/fpls.2018.01768

10.1270/jsbbs.65.298

[51] Anjum SA, Wang LC, Farooq M, Hussain M, Xue LL, Zou CM. Brassinolide application improves the drought tolerance in maize through modulation of enzymatic antioxidants and leaf gas exchange. Journal of Agronomy and Crop Science.

[49] Begcy K, Sandhu J, Walia H. Transient heat stress during early seed development primes germination and seedling establishment in rice. Frontiers in Plant Science. 2018;**9**:17-68. DOI:

[50] Li R, Zeng Y, Xu J, Wang Q, Wu F, Cao M, et al. Genetic variation for maize root architecture in response to drought stress at the seedling stage. Breeding Science. 2015;**65**(4):298-307. DOI:

**180**

[60] Tao F, Zhao Z. Adaptation of maize production to climate change in North China Plain: Quantify the relative contributions of adaptation options. European Journal of Agronomy. 2010;**33**:103-116

[61] Muchow RC. Effect of high temperature on grain-growth in fieldgrown maize. Field Crops Research. 1990;**23**:145-158

[62] Singletary GW, Banisadr R, Keeling PL. Heat stress during grain filling in maize, effects on carbohydrate storage and metabolism. Australian Journal of Plant Physiology. 1994;**21**:829-841

[63] Suwa R, Hakata H, Hara H, El-Shemy HA, Adu-Gyamfi JJ, Nguyen NT, et al. High temperature effects on photosynthate partitioning and sugar metabolism during ear expansion in maize (*Zea mays* L.) genotypes. Plant Physiology and Biochemistry. 2010;**48**:124-130. DOI: 10.1071/PP9910259

[64] Hawkins E, Fricker TE, Challinor AJ, Ferro CA, Ho CK, Osborne TM. Increasing influence of heat stress on French maize yields from the 1960s to the 2030s. Global Change Biology. 2013;**19**(3):937-947. DOI: 10.1111/gcb.12069

[65] Harrison L, Michaelsen J, Funk C, Husak G. Effects of temperature changes on maize production in Mozambique. Climate Research. 2011;**46**(3):211-222

[66] Hatfield JL, Dold C. Climate change impacts on corn phenology and productivity. In: Amanullah K, Fahad S, editors. Corn: Production and Human Health in Changing Climate. 2018. p. 95. DOI: 10.5772/intechopen.76933

[67] Alam A, Seetharam K, Zaidi PH, Dinesh A, Vinayan MT, Kumar NU. Dissecting heat stress tolerance in tropical maize (*Zea mays* L.). Field Crops Research. 2017;**204**:110-119

[68] Edreira JI, Mayer LI, Otegui ME. Heat stress in temperate and tropical maize hybrids: Kernel growth, water relations and assimilate availability for grain filling. Field Crops Research. 2014;**166**:162-172

[69] Rahman HU. Genetic analysis of stomatal conductance in upland cotton *(Gossypium hirsutum* L.*)* under contrasting temperature regimes. Journal of Agriculture Science. 2005;**143**:161-168

[70] Talwar HS, Takeda H, Yashima S, Senboku T. Growth and photosynthetic responses of groundnut genotypes to high temperature. Crop Science. 1999;**39**:60-466. DOI: 10.2135/cropsci19 99.0011183X0039000200027x

[71] Ristic Z, Momčilović I, Bukovnik U, Prasad PV, Fu J, DeRidder BP, et al. Rubisco activase and wheat productivity under heat-stress conditions. Journal of Experimental Botany. 2009;**60**(14):4003-4014

[72] Hussain HA, Men S, Hussain S, Chen Y, Ali S, Zhang S, et al. Interactive effects of drought and heat stresses on morpho-physiological attributes, yield, nutrient uptake and oxidative status in maize hybrids. Scientific Reports. 2019;**9**:3890. DOI: 10.1038/ s41598-019-40362-7

[73] Brdar MD, Kraljevíc-Balalíc MM, Kobiljski BD. The parameters of grain filling and yield components in common wheat (*Triticum aestivum* L.) and

durum wheat (*Triticum turgidum* L.*var*. durum). Central European Journal of Biology. 2008;**3**:75-82. DOI: 10.2478/ s11535-007-0050-x

[74] Pierre CS, Peterson CJ, Ross AS, Ohm J, Verhoeven MC, Larson M, et al. Wheat grain quality changes with genotype, nitrogen fertilization, and water stress. Agronomy Journal. 2008;**100**:414-420. DOI: 10.2134/ agrojnl2007.0166

[75] El Sabagh A, Barutçular C, Saneoka H. Assessment of drought tolerance maize hybrids at grain growth stage in Mediterranean area. International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering. 2015;**9**:989-992

[76] Gooding MJ, Ellis RH, Shewry PR. Effects of restricted water availability and increased temperature on the grain filling, drying and quality of winter wheat. Journal of Cereal Science. 2003;**37**:295-309. DOI: 10.1006/ jcrs.2002.0501

[77] Mousavi H, Lack S, Alavi FM. Analysis of correlation and stepwise regression between grain protein yield and related traits of maize in conditions of drought stress and zinc sulfate spraying. International Journal of Agriculture and Crop Sciences. 2013;**5**:2783-2788

[78] Oury F, Godin C. Yield and grain protein concentration in bread wheat: How to use the negative relationship between the two characters to identify favorable genotypes? Euphytica. 2007;**157**:45-57. DOI: 10.1007/ s10681-0079395-5

[79] Yousaf MI, Hussain K, Hussain S, Ghani A, Arshad M, Mumtaz A, et al. Characterization of indigenous and exotic maize hybrids for grain yield and quality traits under heat stress. International Journal of Agriculture

and Biology. 2018;**20**(2):333-337. DOI: 10.17957/IJAB/15.0493

[80] Lu D, Cai X, Yan F, Sun X, Wang X, Lu W. Effects of high temperature after pollination on physicochemical properties of waxy maize flour during grain development. Journal of the Science of Food and Agriculture. 2014;**94**:1416-1421. DOI: 10.1002/ jsfa.6433

[81] Yang JC, Zhang JH. Grain filling of cereals under soil drying. New Phytologist. 2006;**169**:223-236. DOI: 10.1111/j.1469-8137.2005.01597.x

[82] Plaut Z, Butow BJ, Blumenthal CS, Wrigley CW. Transport of dry matter into developing wheat kernels and its contribution to grain yield under post-anthesis water deficit and elevated temperature. Field Crops Research. 2004;**86**(2-3):85-198

[83] Zare M, Ghahremaninejad M, Bazrafshan F. Influence of drought stress on some traits in five mung bean (*Vigna radiata* (L.) R. Wilczek) genotypes. International Journal of Agronomy and Plant Production. 2012;**3**:234-240

[84] Duthion C, Pigeaire A. Seed lengths corresponding to the final stage in seed abortion of three grain legumes. Crop Science. 1991;**31**:1579-1583. DOI: 10.2135/cropsci1991.0011183X0031000 60040x

[85] Hurkman WJ, McCue KF, Altenbach SB, Korn A, Tanaka CK, Kothari KM. Effect of temperature on expression of genes encoding enzymes for starch biosynthesis in developing wheat endosperm. Plant Science. 2003;**164**:873-881. DOI: 10.1016/ S0168-9452(03)00076-1

[86] Yamakawa H, Hakata M. Atlas of rice grain filling-related metabolism under high temperature: Joint analysis of metabolome and transcriptome

**183**

ijms14059643

*Maize Adaptability to Heat Stress under Changing Climate*

[93] Wani SH, Kumar V, Shriram V, Sah SK. Phytohormones and their metabolic engineering for abiotic stress tolerance in crop plants. Crop Journal.

[94] Finger R, Hediger W, Schmid S. Irrigation as adaptation strategy to climate change—A biophysical and economic appraisal for Swiss maize production. Climatic Change.

2016;**4**(3):162-176

2011;**105**(3-4):509-528

2013;**19**(11):3481-3492

10.1038/nclimate2153

2009;**14**:35-41

agronomy6020034

[97] Aguilera E, Lassaletta L, Gattinger A, Gimeno BS, et al. Managing soil carbon for climate change mitigation and adaptation in Mediterranean cropping systems: A meta-analysis. Agriculture, Ecosystems & Environment. 2013;**15**(168):25-36

[99] Dong X, Xu W, Zhang Y,

[95] Liu Z, Hubbard KG, Lin X, Yang X. Negative effects of climate warming on maize yield are reversed by the changing of sowing date and cultivar selection in Northeast China. Global Change Biology.

[96] Challinor AJ, Watson J, Lobell DB, Howden SM, Smith DR, Chhetri N. A meta-analysis of crop yield under climate change and adaptation. Nature Climate Change. 2014;**4**(4):287. DOI:

[98] Dai MH, Shan CG, Wang P. Effect of temperature and solar ecological factors on spring maize production. Journal of China Agricultural University.

Leskovar D. Effect of irrigation timing on root zone soil temperature, root growth and grain yield and chemical composition in corn. Agronomy. 2016;**6**(2):34. DOI: 10.3390/

[100] Yuan BZ, Sun J, Nishiyama S. Effect

of drip irrigation on strawberry growth and yield inside a plastic

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

demonstrated inhibition of starch accumulation and induction of amino-acid accumulation. Plant Cell

[87] Daniel C, Triboi E. Effects of temperature and nitrogen nutrition on the grain composition of winter wheat: Effects on gliadin content and composition. Journal of Cereal Science.

[88] Erekul O, Köhn W. Effect of weather and soil conditions on yield components and bread making quality of winter wheat (*Triticum aestivum* L.) and winter triticale (*Triticosecale Wittm*.) varieties in North-East Germany. Journal of Agronomy and Crop Science.

Physiology. 2010;**51**:795-809

2000;**32**:45-56

2006;**192**(6):452-464

[89] Castro M, Peterson CJ, Dalla Rizza M, Dellavalle PD, Vázquez D, Ibanez V, et al. Influence of heat stress on wheat grain characteristics and protein molecular weight distribution. In: Buck HT, Nisi JE, Salomon N, editors. Wheat Production in Stressed Environment. The Netherlands: Springer; 2007. pp. 365-371

[90] Majoul T, Bancel E, Triboï E, Ben Hamida J, Branlard G. Proteomic

[91] Dias AS, Bagulho AS, Lidon FC. Ultra-structure and biochemical traits of bread and durum wheat grains under heat stress. Brazzilian Journal of Plant

analysis of the effect of heat stress on hexaploid wheat grain: Characterization of heat-responsive proteins from total endosperm. Proteomics. 2003;**3**:175-183

Physiology. 2008;**20**:323-333

[92] Hasanuzzaman M, Nahar K, Alam MM, Roychowdhury R,

Journal of Molecular Sciences. 2013;**14**(5):9643-9684. DOI: 10.3390/

Fujita M. Physiological, biochemical, and molecular mechanisms of heat stress tolerance in plants. International *Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

demonstrated inhibition of starch accumulation and induction of amino-acid accumulation. Plant Cell Physiology. 2010;**51**:795-809

*Plant Stress Physiology*

s11535-007-0050-x

agrojnl2007.0166

2015;**9**:989-992

jcrs.2002.0501

2013;**5**:2783-2788

s10681-0079395-5

durum wheat (*Triticum turgidum* L.*var*. durum). Central European Journal of Biology. 2008;**3**:75-82. DOI: 10.2478/

and Biology. 2018;**20**(2):333-337. DOI:

[80] Lu D, Cai X, Yan F, Sun X, Wang X, Lu W. Effects of high temperature after pollination on physicochemical properties of waxy maize flour during grain development. Journal of the Science of Food and Agriculture. 2014;**94**:1416-1421. DOI: 10.1002/

[81] Yang JC, Zhang JH. Grain filling of cereals under soil drying. New Phytologist. 2006;**169**:223-236. DOI: 10.1111/j.1469-8137.2005.01597.x

[82] Plaut Z, Butow BJ, Blumenthal CS, Wrigley CW. Transport of dry matter into developing wheat kernels and its contribution to grain yield under post-anthesis water deficit and elevated temperature. Field Crops Research.

[83] Zare M, Ghahremaninejad M, Bazrafshan F. Influence of drought stress on some traits in five mung bean (*Vigna radiata* (L.) R. Wilczek) genotypes. International Journal of Agronomy and Plant Production.

[84] Duthion C, Pigeaire A. Seed lengths corresponding to the final stage in seed abortion of three grain legumes. Crop Science. 1991;**31**:1579-1583. DOI: 10.2135/cropsci1991.0011183X0031000

[85] Hurkman WJ, McCue KF, Altenbach SB, Korn A, Tanaka CK, Kothari KM. Effect of temperature on expression of genes encoding enzymes for starch biosynthesis in developing wheat endosperm. Plant Science. 2003;**164**:873-881. DOI: 10.1016/

S0168-9452(03)00076-1

[86] Yamakawa H, Hakata M. Atlas of rice grain filling-related metabolism under high temperature: Joint analysis of metabolome and transcriptome

2004;**86**(2-3):85-198

2012;**3**:234-240

60040x

10.17957/IJAB/15.0493

jsfa.6433

[74] Pierre CS, Peterson CJ, Ross AS, Ohm J, Verhoeven MC, Larson M, et al. Wheat grain quality changes with genotype, nitrogen fertilization, and water stress. Agronomy Journal. 2008;**100**:414-420. DOI: 10.2134/

[75] El Sabagh A, Barutçular C, Saneoka H. Assessment of drought tolerance maize hybrids at grain growth stage in Mediterranean area. International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering.

[76] Gooding MJ, Ellis RH, Shewry PR. Effects of restricted water availability and increased temperature on the grain filling, drying and quality of winter wheat. Journal of Cereal Science. 2003;**37**:295-309. DOI: 10.1006/

[77] Mousavi H, Lack S, Alavi FM. Analysis of correlation and stepwise regression between grain protein yield and related traits of maize in conditions of drought stress and zinc sulfate spraying. International Journal of Agriculture and Crop Sciences.

[78] Oury F, Godin C. Yield and grain protein concentration in bread wheat: How to use the negative relationship between the two characters to identify favorable genotypes? Euphytica. 2007;**157**:45-57. DOI: 10.1007/

[79] Yousaf MI, Hussain K, Hussain S, Ghani A, Arshad M, Mumtaz A, et al. Characterization of indigenous and exotic maize hybrids for grain yield and quality traits under heat stress. International Journal of Agriculture

**182**

[87] Daniel C, Triboi E. Effects of temperature and nitrogen nutrition on the grain composition of winter wheat: Effects on gliadin content and composition. Journal of Cereal Science. 2000;**32**:45-56

[88] Erekul O, Köhn W. Effect of weather and soil conditions on yield components and bread making quality of winter wheat (*Triticum aestivum* L.) and winter triticale (*Triticosecale Wittm*.) varieties in North-East Germany. Journal of Agronomy and Crop Science. 2006;**192**(6):452-464

[89] Castro M, Peterson CJ, Dalla Rizza M, Dellavalle PD, Vázquez D, Ibanez V, et al. Influence of heat stress on wheat grain characteristics and protein molecular weight distribution. In: Buck HT, Nisi JE, Salomon N, editors. Wheat Production in Stressed Environment. The Netherlands: Springer; 2007. pp. 365-371

[90] Majoul T, Bancel E, Triboï E, Ben Hamida J, Branlard G. Proteomic analysis of the effect of heat stress on hexaploid wheat grain: Characterization of heat-responsive proteins from total endosperm. Proteomics. 2003;**3**:175-183

[91] Dias AS, Bagulho AS, Lidon FC. Ultra-structure and biochemical traits of bread and durum wheat grains under heat stress. Brazzilian Journal of Plant Physiology. 2008;**20**:323-333

[92] Hasanuzzaman M, Nahar K, Alam MM, Roychowdhury R, Fujita M. Physiological, biochemical, and molecular mechanisms of heat stress tolerance in plants. International Journal of Molecular Sciences. 2013;**14**(5):9643-9684. DOI: 10.3390/ ijms14059643

[93] Wani SH, Kumar V, Shriram V, Sah SK. Phytohormones and their metabolic engineering for abiotic stress tolerance in crop plants. Crop Journal. 2016;**4**(3):162-176

[94] Finger R, Hediger W, Schmid S. Irrigation as adaptation strategy to climate change—A biophysical and economic appraisal for Swiss maize production. Climatic Change. 2011;**105**(3-4):509-528

[95] Liu Z, Hubbard KG, Lin X, Yang X. Negative effects of climate warming on maize yield are reversed by the changing of sowing date and cultivar selection in Northeast China. Global Change Biology. 2013;**19**(11):3481-3492

[96] Challinor AJ, Watson J, Lobell DB, Howden SM, Smith DR, Chhetri N. A meta-analysis of crop yield under climate change and adaptation. Nature Climate Change. 2014;**4**(4):287. DOI: 10.1038/nclimate2153

[97] Aguilera E, Lassaletta L, Gattinger A, Gimeno BS, et al. Managing soil carbon for climate change mitigation and adaptation in Mediterranean cropping systems: A meta-analysis. Agriculture, Ecosystems & Environment. 2013;**15**(168):25-36

[98] Dai MH, Shan CG, Wang P. Effect of temperature and solar ecological factors on spring maize production. Journal of China Agricultural University. 2009;**14**:35-41

[99] Dong X, Xu W, Zhang Y, Leskovar D. Effect of irrigation timing on root zone soil temperature, root growth and grain yield and chemical composition in corn. Agronomy. 2016;**6**(2):34. DOI: 10.3390/ agronomy6020034

[100] Yuan BZ, Sun J, Nishiyama S. Effect of drip irrigation on strawberry growth and yield inside a plastic

greenhouse. Biosystems Engineering. 2004;**87**(2):237-245

[101] Maestri E, Klueva N, Perrotta C. Molecular genetics of heat tolerance and heat shock proteins in cereals. Plant Molecular Biology. 2002;**48**:667-681. DOI: 10.1023/A:1014826730024

[102] Gong M, Chen SN, Song YQ, Li ZG. Effect of calcium and calmodulin on intrinsic heat tolerance in relation to antioxidant systems in maize seedlings. Australian Journal of Plant Physiology. 1997;**24**:371-379

[103] Vardhini BV, Anjum NA. Brassinosteroids make plant life easier under abiotic stresses mainly by modulating major components of antioxidant defense system. Frontiers in Environmental Science. 2015;**2**:1-16

[104] Sharma N, Hundal GS, Sharma I, Bhardwaj R. 28-Homobrassinolide alters protein content and activities of glutathione-s-transferase and polyphenol oxidase in *Raphanus sativus* L. plants under heavy metal stress. Toxicology International. 2014;**21**(1):44-50. DOI: 10.4103/0971-6580.128792

[105] Mittler R, Finka A, Goloubinoff P. How do plants feel the heat? Trends in Biochemical Sciences. 2011;**37**:118-125

[106] Xu Y, Gianfagna T, Huang B. Proteomic changes associated with expression of a gene (ipt) controlling cytokinin synthesis for improving heat tolerance in a perennial grass species. Journal of Experimental Botany. 2010;**61**:3273-3289

[107] Dhakal Y, Meena RS, De N, Verma SK, Singh A. Growth, yield and nutrient content of mungbean (*Vigna radiata* L.) in response to INM in eastern Uttar Pradesh, India. Bangladesh Journal of Botany**.** 2015;**44**(3):479-482

[108] Dhakal Y, Meena RS, Kumar S. Effect of INM on nodulation, yield, quality and available nutrient status in soil after harvest of green gram. Legume Research. 2016;**39**(4):590-594

[109] Miura K, Tada Y. Regulation of water, salinity, and cold stress responses by salicylic acid. Frontiers in Plant Science. 2014;**5**:4. DOI: 10.3389/ fpls.2014.00004

[110] Hara M, Furukawa J, Sato A, Mizoguchi T, Miura K. Abiotic stress and role of salicylic acid in plants. In: Ahmad P, Prasad M, editors. Abiotic Stress Responses in Plants. New York, NY: Springer; 2012. pp. 235-251

[111] Meena RS, Yadav RS. Yield and profitability of groundnut *(Arachis hypogaea* L) as influenced by sowing dates and nutrient levels with different varieties. Legume Research. 2015;**38**(6):791-797

[112] Meena RS, Dhakal Y, Bohra JS, Singh SP, Singh MK, Sanodiya P. Influence of bioinorganic combinations on yield, quality and economics of mungbean. American Journal of Experimental Agriculture. 2015;**8**(3):159-166

[113] Yamaguchi S. Gibberellin metabolism and its regulation. Annual Review of Plant Biology. 2008;**59**:225-251

[114] Choudhary SP, Yu JQ, Yamaguchi-Shinozaki K, Shinozaki K, Tran LS. Benefits of brassinosteroid crosstalk. Trends in Plant Science. 2012;**17**(10):594-605

[115] Singh A, Meena RS. Response of bioregulators and irrigation on plant height of Indian mustard (*Brassica juncea* L.). Journal of Oilseed Brassica. 2020;**11**(**1**):9-14

[116] Cakmak I. Plant nutrition research: Priorities to meet human needs for food in sustainable ways. Plant and Soil. 2002;**247**:3-24

**185**

*Maize Adaptability to Heat Stress under Changing Climate*

and yield parameters of bread wheat (*Triticum aestivum* L.) cultivars under salinity and heat stress. Internatıonal Journal of Agriculture & Biology.

[125] Zhao H, Dai T, Jiang D, Cao W. Effects of high temperature on key enzymes involved in starch and protein formation in grains of two wheat cultivars. Journal of Agronomy and Crop Science. 2008;**194**:47-54

[126] Shanahan JF, Edwards IB, Quick JS, Fenwick JR. Membrane thermostability and heat tolerance of spring wheat. Crop Science. 1990;**30**:247-251

[127] Ibrahim AMH, Quick JS. Genetic control of high temperature tolerance in wheat as measured by membrane thermal stability. Crop Science.

[128] Towill LE, Mazur P. Studies on the reduction of 2,3,5-triphenyl tetrazolium chloride as a viability assay for plant tissue culture. Canadian Journal of

2008;**10**(6):619-626

2001;**41**:1405-1407

pp.006163

Botany. 1974;**53**:1097-1102

[129] Yu Q, Hlavacka A, Matoh T, Volkmann D, Menzel D, Goldbach HE, et al. Short-term boron deprivation inhibits endocytosis of cell wall pectins in meristematic cells of maize and wheat root apices. Plant physiology. 2002;**30**(1):415-421. DOI: 10.1104/

[130] Schoper JB, Lambert RJ, Vasilas BL, Westgate ME. Plant factors controlling seed set in maize—The influence of silk, pollen, and ear-leaf water status and tassel heat-temperature at pollination. Plant Physiology. 1987;**83**:121-125

[131] Frova C, Portaluppi P, Villa M, Sari GM. Sporophytic and gametophytic

[132] Meena RS, Kumar V, Yadav GS, Mitran T. Response and interaction

components of thermotolerance affected by pollen selection. Journal of

Heredity. 1995;**86**(1):50-54

*DOI: http://dx.doi.org/10.5772/intechopen.92396*

[117] Waraich EA, Ahmad R, Ashraf MY, Saifullah AM. Improving agricultural water use efficiency by nutrient management in crop plants. Acta Agriculturae Scandinavica, Section B: Plant Soil Science. 2011;**61**(4):291-304

[118] Waraich EA, Ahmad R, Halim A, Aziz T. Alleviation of temperature stress by nutrient management in crop plants: A review. Journal of Soil Science and Plant Nutrition. 2012;**12**(2):221-244

[119] Meena RS, Lal R, Yadav GS. Long term impacts of topsoil depth and amendments on soil physical and hydrological properties of an Alfisol in central Ohio, USA. Geoderma.

[120] Meena RS, Kumar S, Datta R, Lal R, Vijayakumar V, Britnicky M, et al. Impact of agrochemicals on soil microbiota and management: A review.

Land. 2020;**9**:34. DOI: 10.1016/j.

[121] Reynolds MP, Singh RP, Ibrahim A, Ageeb OAA,

[122] Reynolds MP, Rebetzke G, Pellegrinesci A, Trethowan R. Dought adaptation in wheat. In: Ribaut JM, editor. Drought Tolerance in Cereals.

New York: Haworth Food & Agricultural Products Press; 2006.

Larque-Saavedra A, Quick JS. Evaluating physiological traits to complement empirical selection for wheat in warm environments. Euphytica.

[123] Amani I, Fischer RA, Reynolds MP.

Canopy temperature depression associated with yield of irrigated spring wheat cultivars in a hot climate. Journal of Agronomy and Crop Science.

[124] Freeha A, Abdul W, Farrukh J, Muhammad A. Influence of foliar applied thiurea on flag leaf gas exchange

geoderma.2019.114164

1998;**100**:85-94

pp. 402-436

1996;**176**:119-129

2020;**363**:1141164

*Maize Adaptability to Heat Stress under Changing Climate DOI: http://dx.doi.org/10.5772/intechopen.92396*

[117] Waraich EA, Ahmad R, Ashraf MY, Saifullah AM. Improving agricultural water use efficiency by nutrient management in crop plants. Acta Agriculturae Scandinavica, Section B: Plant Soil Science. 2011;**61**(4):291-304

*Plant Stress Physiology*

2004;**87**(2):237-245

1997;**24**:371-379

greenhouse. Biosystems Engineering.

quality and available nutrient status in soil after harvest of green gram. Legume

Research. 2016;**39**(4):590-594

fpls.2014.00004

2015;**38**(6):791-797

2015;**8**(3):159-166

2008;**59**:225-251

[112] Meena RS, Dhakal Y, Bohra JS, Singh SP, Singh MK, Sanodiya P. Influence of bioinorganic combinations on yield, quality and economics of mungbean. American Journal of Experimental Agriculture.

[113] Yamaguchi S. Gibberellin metabolism and its regulation. Annual Review of Plant Biology.

Benefits of brassinosteroid crosstalk. Trends in Plant Science.

2012;**17**(10):594-605

2020;**11**(**1**):9-14

2002;**247**:3-24

[114] Choudhary SP, Yu JQ, Yamaguchi-Shinozaki K, Shinozaki K, Tran LS.

[115] Singh A, Meena RS. Response of bioregulators and irrigation on plant height of Indian mustard (*Brassica juncea* L.). Journal of Oilseed Brassica.

[116] Cakmak I. Plant nutrition research: Priorities to meet human needs for food in sustainable ways. Plant and Soil.

[109] Miura K, Tada Y. Regulation of water, salinity, and cold stress responses by salicylic acid. Frontiers in Plant Science. 2014;**5**:4. DOI: 10.3389/

[110] Hara M, Furukawa J, Sato A, Mizoguchi T, Miura K. Abiotic stress and role of salicylic acid in plants. In: Ahmad P, Prasad M, editors. Abiotic Stress Responses in Plants. New York, NY: Springer; 2012. pp. 235-251

[111] Meena RS, Yadav RS. Yield and profitability of groundnut *(Arachis hypogaea* L) as influenced by sowing dates and nutrient levels with

different varieties. Legume Research.

[101] Maestri E, Klueva N, Perrotta C. Molecular genetics of heat tolerance and heat shock proteins in cereals. Plant Molecular Biology. 2002;**48**:667-681. DOI: 10.1023/A:1014826730024

[102] Gong M, Chen SN, Song YQ, Li ZG. Effect of calcium and calmodulin on intrinsic heat tolerance in relation to antioxidant systems in maize seedlings. Australian Journal of Plant Physiology.

[103] Vardhini BV, Anjum NA.

Brassinosteroids make plant life easier under abiotic stresses mainly by modulating major components of antioxidant defense system. Frontiers in Environmental Science. 2015;**2**:1-16

[104] Sharma N, Hundal GS, Sharma I, Bhardwaj R. 28-Homobrassinolide alters

[105] Mittler R, Finka A, Goloubinoff P. How do plants feel the heat? Trends in Biochemical Sciences. 2011;**37**:118-125

[106] Xu Y, Gianfagna T, Huang B. Proteomic changes associated with expression of a gene (ipt) controlling cytokinin synthesis for improving heat tolerance in a perennial grass species. Journal of Experimental Botany.

[107] Dhakal Y, Meena RS, De N, Verma SK, Singh A. Growth, yield and nutrient content of mungbean (*Vigna radiata* L.) in response to INM in eastern Uttar Pradesh, India. Bangladesh Journal

of Botany**.** 2015;**44**(3):479-482

[108] Dhakal Y, Meena RS, Kumar S. Effect of INM on nodulation, yield,

protein content and activities of glutathione-s-transferase and polyphenol oxidase in *Raphanus sativus* L. plants under heavy metal stress. Toxicology International.

2014;**21**(1):44-50. DOI: 10.4103/0971-6580.128792

2010;**61**:3273-3289

**184**

[118] Waraich EA, Ahmad R, Halim A, Aziz T. Alleviation of temperature stress by nutrient management in crop plants: A review. Journal of Soil Science and Plant Nutrition. 2012;**12**(2):221-244

[119] Meena RS, Lal R, Yadav GS. Long term impacts of topsoil depth and amendments on soil physical and hydrological properties of an Alfisol in central Ohio, USA. Geoderma. 2020;**363**:1141164

[120] Meena RS, Kumar S, Datta R, Lal R, Vijayakumar V, Britnicky M, et al. Impact of agrochemicals on soil microbiota and management: A review. Land. 2020;**9**:34. DOI: 10.1016/j. geoderma.2019.114164

[121] Reynolds MP, Singh RP, Ibrahim A, Ageeb OAA, Larque-Saavedra A, Quick JS. Evaluating physiological traits to complement empirical selection for wheat in warm environments. Euphytica. 1998;**100**:85-94

[122] Reynolds MP, Rebetzke G, Pellegrinesci A, Trethowan R. Dought adaptation in wheat. In: Ribaut JM, editor. Drought Tolerance in Cereals. New York: Haworth Food & Agricultural Products Press; 2006. pp. 402-436

[123] Amani I, Fischer RA, Reynolds MP. Canopy temperature depression associated with yield of irrigated spring wheat cultivars in a hot climate. Journal of Agronomy and Crop Science. 1996;**176**:119-129

[124] Freeha A, Abdul W, Farrukh J, Muhammad A. Influence of foliar applied thiurea on flag leaf gas exchange and yield parameters of bread wheat (*Triticum aestivum* L.) cultivars under salinity and heat stress. Internatıonal Journal of Agriculture & Biology. 2008;**10**(6):619-626

[125] Zhao H, Dai T, Jiang D, Cao W. Effects of high temperature on key enzymes involved in starch and protein formation in grains of two wheat cultivars. Journal of Agronomy and Crop Science. 2008;**194**:47-54

[126] Shanahan JF, Edwards IB, Quick JS, Fenwick JR. Membrane thermostability and heat tolerance of spring wheat. Crop Science. 1990;**30**:247-251

[127] Ibrahim AMH, Quick JS. Genetic control of high temperature tolerance in wheat as measured by membrane thermal stability. Crop Science. 2001;**41**:1405-1407

[128] Towill LE, Mazur P. Studies on the reduction of 2,3,5-triphenyl tetrazolium chloride as a viability assay for plant tissue culture. Canadian Journal of Botany. 1974;**53**:1097-1102

[129] Yu Q, Hlavacka A, Matoh T, Volkmann D, Menzel D, Goldbach HE, et al. Short-term boron deprivation inhibits endocytosis of cell wall pectins in meristematic cells of maize and wheat root apices. Plant physiology. 2002;**30**(1):415-421. DOI: 10.1104/ pp.006163

[130] Schoper JB, Lambert RJ, Vasilas BL, Westgate ME. Plant factors controlling seed set in maize—The influence of silk, pollen, and ear-leaf water status and tassel heat-temperature at pollination. Plant Physiology. 1987;**83**:121-125

[131] Frova C, Portaluppi P, Villa M, Sari GM. Sporophytic and gametophytic components of thermotolerance affected by pollen selection. Journal of Heredity. 1995;**86**(1):50-54

[132] Meena RS, Kumar V, Yadav GS, Mitran T. Response and interaction

of *Bradyrhizobium japonicum* and *Arbuscular mycorrhizal* fungi in the soybean rhizosphere: A review. Plant Growth Regulators. 2018;**84**:207-223

[133] Pottorff M, Roberts PA, Close TJ, Lonardi S, Wanamaker S, Ehlers JD. Identification of candidate genes and molecular markers for heatinduced brown discoloration of seed coats in cowpea [*Vigna unguiculata* (L.) Walp]. BMC Genomics. 2014;**15**:328. DOI: 10.1186/1471-2164-15-328

[134] Lavania D, Siddiqui MH, Al-Whaibi MH, Singh AK, Kumar R, Grover A. Genetic approaches for breeding heat stress tolerance in faba bean (*Vicia faba* L.). Acta Physiologiae Plantarum. 2015;**37**:1737. DOI: 10.1007/ s11738-014-1737-z

[135] Bett K, Ramsay L, Sharpe A. Lentil genome sequencing: Establishing a comprehensive platform for molecular breeding. In: 6th International Food Legume Res. In Conf. and 7th International Conf. on Legume Genetics. Saskatoon, Saskatchewan, Canada. Crop Development Center: Saskatoon, SK. 2014. p. 19

[136] Manolio TA. Genome wide association studies and assessment of the risk of disease. New England Journal of Medicine. 2010;**363**:66-176

[137] Bush WS, Moore JH. Genomewide association studies. PLoS Computational Biology. 2012;**8**:e1002822

[138] Huang Z, Zhang X, Zheng G, Gutterman Y. Influence of light, temperature, salinity and storage on seed germination of Haloxylon ammodendron. Journal of Arid Environments. 2003;**55**(3):453-464

[139] Iqbal MA, Mian MA. Boosting spring planted irrigated maize

(*Zea mays* L.) grain yield with planting patterns adjustment. American-Eurasian Journal of Agricultural & Environmental Sciences. 2015;**15**(3):315-319

**187**

Section 3

Molecular Mechanisms

against Abiotic Stresses

## Section 3
