Role of Fungi in Agriculture

*Muthuraman Yuvaraj and Murugaragavan Ramasamy*

### **Abstract**

Fungi are a group of eukaryotic organisms and source of food, organic acids, alcohol, antibiotics, growth-promoting substances, enzymes, and amino acids. They include microorganisms like molds, yeasts, and mushrooms. They live on dead or living plants or animals' tissue. Fungi are very different from other living organisms; they are the primary decomposers of substances in the ecological system. Fungi are tremendous decomposer of organic waste material and most readily attack cellulose, lignins, gums, and other organic complex substances. Fungi can act also under a wide range of soil reaction from acidic to alkaline soil reactions. Fungi conjointly play a basic role in different physiological processes as well as mineral and water uptake, chemical change, stomatal movement, and biosynthesis of compounds termed biostimulants, auxins, lignan, and ethylene to enhance the flexibility of plants to ascertain and cope environmental stresses like drought, salinity, heat, cold, and significant metals.

**Keywords:** fungi, mycorrhiza, plant growth

### **1. Introduction**

The microorganism was used from the very beginning of the civilization in the agriculture and industrial processes even before their existence was well known. Production of fermented beverages, bread and vinegar are traditional processers practiced from the time of early civilization. Recent advancement in our understanding about the genetics, physiology, and biochemistry of fungi, has led the exploitation of fungi for preparation of different agriculture and industrial products of economic importance. All the environmental factors influence the distribution of the fungal flora of soil [1, 2].

The primary functions of filamentous fungi in the soil are to degrade organic matter and help in soil aggregation. Besides this property, bound species of *Alternaria, genus Aspergillus, Cladosporium, Dematium, Gliocladium, Humicola* and *Metarhizium* manufacture substance like organic compounds in soil and therefore could also be necessary for the maintenance of soil organic matter. Plant growth regulators and chemical fertilizers have been used to increase crop production [3, 4]. Application of chemical fertilizers to crop plants negatively affects human health and environments. Recent studies have focused on identification of alternative methods to enhance plant productivity and protect the soil. Soil borne microbes can enter roots and establish their population in plants as endophytes, and many plant-associated fungi are well known for their capacity to promote plant growth; however, the relationship between these microbes and plants is still uncertain [5]. Microorganisms have the ability to produce phytohormones, solubilize insoluble

phosphate and convert complex organic substances to simple forms. Endophytic fungi have also been shown to impart plants with tolerance to salt, drought, heat and diseases [6].

The four endophytic fungi (GM-1, GM-2, GM-3, and GM-4) were tested for their ability to improve soybean plant growth under salinity stress conditions. The seed germination and plant growth were higher in seeds pretreated with endophytic fungal cultures than their controls. The positive influence of fungi on plant growth was supported by gibberellins analysis of culture filtrate (CF), which showed wide diversity and various concentrations of Gibberellic acids [7].

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the other isolates [8].

The fungal associations with plants influence the primary and secondary metabolism of plants at all developmental stages. Photosynthesis is an important primary mechanism, and the main source of energy for plants. Its efficiency is related to photosynthetic pigments such as chlorophylls and carotenoids. Leaf chlorophyll a was increased in fungi-treated plants more so than in the controls [9].

### **2. Role of soil fungus**

The fungi dominate in low pH or slightly acidic soils where soils tend to be undisturbed [10]. Fungi break down the organic residues so many alternative sorts of microbes will begin to decompose and method the residues into usable merchandise. Approximately 90% of all plants form symbiotic mycorrhizae fungi relationships by forming hyphae networks. Through mycorrhizae the plant obtains mainly phosphate and other minerals, such as zinc and copper, from the soil. The fungus obtains nutrients, such as sugars, from the plant root. This mutually beneficial relationship is called a mycorrhizae network [11].

Soil fungi can grow in a wide range of soil pH but their population is more under acidic conditions because of severe competition with bacteria at neutral pH. A majority of fungi are aerobic and prefer to grow at optimum soil moisture. The contribution of these organisms in biochemical transformation under excessive moisture is negligible [12].

The rhizosphere is a locality next to the basis dominated by soil microbes wherever several chemicals and organic chemistry methods occur. Soil fungi form up to 10–30% of the soil rhizosphere. The fungi ability to produce a wide variety of extracellular enzymes, they are able to break down all kinds of organic matter, decomposing soil components and thereby regulating the balance of carbon and nutrients for maintain soil health. This allows fungi to bridge gaps in the soil to transport nutrients relatively far distances back to the plants [13] (**Tables 1** and **2**).

Soil is a primary source of fungal growth, and is associated with the roots of all plant species. Fungi produce a wide range of bioactive metabolites, which can improve plant growth [14]. In addition, fungi supply inorganic nutrients to plants, such as ammonium, nitrate, and phosphate [15] and they are used as biofertilizers. Rhizosphere microorganisms can overcome competition with other soil factors and survive under variable environmental conditions [16].

**91**

**Table 2.**

*Agricultural application of fungi.*

*Role of Fungi in Agriculture*

AM fungi Dead

AM fungi *Vigna* 

*Trichoderma sp.* Agriculturally

Ectomycorrhizal

Ectomycorrhizal fungi and AM fungi

fungi

**Table 1.**

**Fungal species/ strain**

*Phanerochaete velutina*

*Perisporiopsis lateritia*

*Navisporus floccosus*

*DOI: http://dx.doi.org/10.5772/intechopen.89718*

vegetation in soil

Leaves of *Hevea* sp.

M fungi *Pinus taeda* Decomposing

*unguiculata*

*Trichoderma sp. Arabidopsis sp.* Auxins dependent

important crops

Higher plant species

Agricultural crops

**Plant type Fungi-mediated** 

Wood Decomposing

Pleurotus sp. Wood Wood decay Nutrient

M fungi *Allium cepa* Plant growth Improved

**response**

wood

Wood Wood decay Nutrient

organic matter

mechanism

Phenolic compounds degradation

Stomatal physiology and water relation

*Soil-beneficial fungi on different physiological and catabolic processes in various host plant species.*

Degrade of dead organic

Leaves decay Nutrient

Mineral uptake Improved

**Beneficial effects on plant species**

Nutrient mobilization

Phosphorus translocation

mobilization

mobilization

mobilization

Carbon and nitrogen cycling

nutritional status

nutritional status

Higher biomass production and increased lateral roots formation

Biocontrol Crop management [52] Chalot and

Improved water potential status and increased photosynthesis rate

Plant protection [54] Ha (2010)

**References**

[43] Hodge et al. (2001)

[44] Wells et al. (1998)

[45] Cohen et al. (2002)

[46] Chaverri and Gazis (2010)

[47] Phillips et al. (2012)

[48] Hoorman (2011)

[49] Yaseen et al. (2011)

[50] Albrechtova et al. (2012)

[51] Contreras-Cornejo et al. (2009)

Brun (1998), [53] Harman and Mastouri (2010)

[55] Arnold and Engelbrecht (2007) *Biostimulants in Plant Science*

and diseases [6].

other isolates [8].

**2. Role of soil fungus**

moisture is negligible [12].

(**Tables 1** and **2**).

phosphate and convert complex organic substances to simple forms. Endophytic fungi have also been shown to impart plants with tolerance to salt, drought, heat

The four endophytic fungi (GM-1, GM-2, GM-3, and GM-4) were tested for their ability to improve soybean plant growth under salinity stress conditions. The seed germination and plant growth were higher in seeds pretreated with endophytic fungal cultures than their controls. The positive influence of fungi on plant growth was supported by gibberellins analysis of culture filtrate (CF), which showed wide

Application of rhizospheric fungi is an effective and environmentally friendly method of improving plant growth and controlling many plant diseases. Three predominant fungi (PNF1, PNF2, and PNF3) isolated from the rhizospheric soil of peanut plants were screened for their growth-promoting efficiency on sesame seedlings. Among these isolates, PNF2 significantly increased the shoot length and fresh weight of seedlings compared with controls. Analysis of the fungal culture filtrate showed a higher concentration of indole acetic acid in PNF2 than in the

The fungal associations with plants influence the primary and secondary metabolism of plants at all developmental stages. Photosynthesis is an important primary mechanism, and the main source of energy for plants. Its efficiency is related to photosynthetic pigments such as chlorophylls and carotenoids. Leaf chlorophyll a

The fungi dominate in low pH or slightly acidic soils where soils tend to be undisturbed [10]. Fungi break down the organic residues so many alternative sorts of microbes will begin to decompose and method the residues into usable merchandise. Approximately 90% of all plants form symbiotic mycorrhizae fungi relationships by forming hyphae networks. Through mycorrhizae the plant obtains mainly phosphate and other minerals, such as zinc and copper, from the soil. The fungus obtains nutrients, such as sugars, from the plant root. This mutually beneficial

Soil fungi can grow in a wide range of soil pH but their population is more under

acidic conditions because of severe competition with bacteria at neutral pH. A majority of fungi are aerobic and prefer to grow at optimum soil moisture. The contribution of these organisms in biochemical transformation under excessive

The rhizosphere is a locality next to the basis dominated by soil microbes wherever several chemicals and organic chemistry methods occur. Soil fungi form up to 10–30% of the soil rhizosphere. The fungi ability to produce a wide variety of extracellular enzymes, they are able to break down all kinds of organic matter, decomposing soil components and thereby regulating the balance of carbon and nutrients for maintain soil health. This allows fungi to bridge gaps in the soil to transport nutrients relatively far distances back to the plants [13]

Soil is a primary source of fungal growth, and is associated with the roots of all plant species. Fungi produce a wide range of bioactive metabolites, which can improve plant growth [14]. In addition, fungi supply inorganic nutrients to plants, such as ammonium, nitrate, and phosphate [15] and they are used as biofertilizers. Rhizosphere microorganisms can overcome competition with other soil factors and

was increased in fungi-treated plants more so than in the controls [9].

relationship is called a mycorrhizae network [11].

survive under variable environmental conditions [16].

diversity and various concentrations of Gibberellic acids [7].

**90**


### **Table 1.**

*Soil-beneficial fungi on different physiological and catabolic processes in various host plant species.*


**Table 2.** *Agricultural application of fungi.*

### **3. Ecological plant-microbe interactions**

The microbes and plants along regulate several soil processes as well as the carbon cycle and nutrient utilization. Plant diversity and abundance might modification the complete soil scheme through the discharge of root exudates that attract or inhibit the expansion of specific organisms [17].

### **3.1 Economic advantage of fungi**


### **3.2 Vesicular arbuscular mycorrhiza**

Vesicular arbuscular mycorrhiza (VAM) fungi belong to the *Glomeromycota*. They are primitive fungi at the base of the tree for higher fungi (basidiomycetes). They turn out microscopic structures, or comparatively tiny sporocarps (trufflelike). Just over 200 species of these fungi are described, yet they are capable of forming mycorrhizal associations with the majority of plants. The word mycorrhiza is derived from the classical Greek word for "mushroom" and "root." In a mycorrhizal association, the underground mycellium is in contact with plant roots, but without causing any harm to the plant.

Mycorrhizal fungi accountable in the rising growth of host plant species because of raised nutrient uptake, production of growth-promoting substances and tolerance to drought, salinity and synergistic interactions with other beneficial microorganisms [18]. The soil conditions prevalent in sustainable agriculture are likely to be more favorable to AM fungi than are those under conventional agriculture [19]. The AM fungi are widely distributed in natural and agricultural environments and have been found associated with more than 80% of land plants, ferns, woody gymnosperms and angiosperms and grasses [20].

Arbuscular mycorrhiza fungi (AMF) are beneficial fungal organisms that share symbiotic association with many land plants. The arbuscular mycorrhiza fungi have the potential to improve soil characteristics, thereby promoting plant growth in normal and stressful environments [21]. The arbuscular mycorrhiza fungi colonization enhances plant growth [22] and changes the morphological, nutritional and physiological levels of plants to improve resistance against different abiotic stresses [23]. The arbuscular mycorrhiza fungi inoculation protects *Ocimum basilicum* against salinity stress by improving mineral uptake, chlorophyll synthesis and water use efficiency [24]. Tomato plants inoculated with arbuscular mycorrhiza fungi

**93**

mycorrhizae.

*Role of Fungi in Agriculture*

**3.3 Edible fungi**

*DOI: http://dx.doi.org/10.5772/intechopen.89718*

**3.4 Plant response to AM Fungal inoculation**

manufacturing antibiotics, by parasitizing pathogens [27].

tion is known as mycorrhizal association [28].

i.Ectotrophic mycorrhizae

ii.Endomycorrhizae

(ii) Endomycorrhizae.

**3.5 Exploitation of AM fungi for nutrient uptake and exchange**

forms this types of association are species of *Boletus, Amenita*, etc.

The fungi form a symbiotic association with roots of higher plants, facilitating uptake of plant nutrients, particularly of those which are less mobile this associa-

There are two types of mycorrhizal association (i) Ectotrophic mycorrhizae and

Ectotrophic mycorrhizae, where the fungus forms a mantle or sheath around the root surface and where the mycelium develops intracellularly. The fungi which

Endomycorrhizae, where the fungus develops intracellularly in the root without forming Hartig net. In this association the penetration of roots cells is characterized by the formation of terminal spherical structure called vesicular, which contain oil droplets and phosphorus. This type of mycorrhiza is called vesicular arbuscular

The management of AM fungi is very vital for organic and low-input agriculture systems wherever soil phosphorus is, in general, low, although all

show an increase in the leaf area, nitrogen, potassium, calcium and phosphorous

Fungi can be used to produce material of nutritive value such as vitamins, amino acids, and lipids to make it more nutritious and palatable. Mushrooms are cultivated to yield fruit bodies directly consumed as food and yeast cells, mold mycelium is grown in fermenters to produce single-cell protein which may be used as food.

Soil phosphorus is a critical factor in plant response and responses are generally better under low phosphorus levels. Host genotypes and fungal strains seem to influence the response of plants to inoculation. The worldwide field experiment has provided evidence to show that under marginal P-deficiency soils lacking in effective AM fungal endophytes increase in yield of wheat, maize, barley, potatoes, and cowpea. Increased uptake of zinc has also been shown in AM fungus inoculated peach, maize, wheat and potato in zinc deficiency soils. The AM associations related to increased uptake of sulfur and calcium, improved water absorption and tolerance of plants to water stress in citrus and avocado seedlings have also been noticed. There are also reports of increased levels of cytokinins and chlorophyll by AM fungus- infected plants [26]. Therefore, many researchers were trying to use alternative approaches based on either manipulating or adding microorganisms to enhance plant protection against pathogens. The useful microorganisms (antagonistic bacteria) (e.g., bacteria genus visible radiation, *Bacilli subtilis*) and fungi (e.g., AMF, Trichoderma) contend with plant pathogens for nutrients and house, by

contents to enhance the plant growth rate compared to controls [25].

show an increase in the leaf area, nitrogen, potassium, calcium and phosphorous contents to enhance the plant growth rate compared to controls [25].

### **3.3 Edible fungi**

*Biostimulants in Plant Science*

**3. Ecological plant-microbe interactions**

or inhibit the expansion of specific organisms [17].

**3.1 Economic advantage of fungi**

**3.2 Vesicular arbuscular mycorrhiza**

without causing any harm to the plant.

sperms and angiosperms and grasses [20].

inexperienced.

The microbes and plants along regulate several soil processes as well as the carbon cycle and nutrient utilization. Plant diversity and abundance might modification the complete soil scheme through the discharge of root exudates that attract

• The saprophytic fungi of decay maintain the never-ending cycle of greenhouse emission that could be the most significant staple for plant chemical processes in nature. They additionally cause rot, decay, and decomposition of animal and plant remains emotional plant nutrients in an exceedingly type offered to

• There are types of fungi they serve to suppress fungi inflicting the sickness disease of the seedlings and thereby influence favorably the expansion of crops.

• Some fungi like *Empusa sepulchrasis, Metarhizium anisopliae,* and *Cordyceps melothac* can be used to control some insect pests. Others parasitic to some insects particularly, some spore-forming ones. The fungi spores sprayed on the crop cuss to regulate them. Colorado potato beetles, citrus rust mites, and spittle-bugs of insect cuss that may be controlled exploitation fungi. These types of fungi form loops on their mycelium which traps and strangle nematodes as the attempt to pass through. They later absorb nutrition from the nematodes.

Vesicular arbuscular mycorrhiza (VAM) fungi belong to the *Glomeromycota*. They are primitive fungi at the base of the tree for higher fungi (basidiomycetes). They turn out microscopic structures, or comparatively tiny sporocarps (trufflelike). Just over 200 species of these fungi are described, yet they are capable of forming mycorrhizal associations with the majority of plants. The word mycorrhiza is derived from the classical Greek word for "mushroom" and "root." In a mycorrhizal association, the underground mycellium is in contact with plant roots, but

Mycorrhizal fungi accountable in the rising growth of host plant species because of raised nutrient uptake, production of growth-promoting substances and tolerance to drought, salinity and synergistic interactions with other beneficial microorganisms [18]. The soil conditions prevalent in sustainable agriculture are likely to be more favorable to AM fungi than are those under conventional agriculture [19]. The AM fungi are widely distributed in natural and agricultural environments and have been found associated with more than 80% of land plants, ferns, woody gymno-

Arbuscular mycorrhiza fungi (AMF) are beneficial fungal organisms that share symbiotic association with many land plants. The arbuscular mycorrhiza fungi have the potential to improve soil characteristics, thereby promoting plant growth in normal and stressful environments [21]. The arbuscular mycorrhiza fungi colonization enhances plant growth [22] and changes the morphological, nutritional and physiological levels of plants to improve resistance against different abiotic stresses [23]. The arbuscular mycorrhiza fungi inoculation protects *Ocimum basilicum* against salinity stress by improving mineral uptake, chlorophyll synthesis and water use efficiency [24]. Tomato plants inoculated with arbuscular mycorrhiza fungi

**92**

Fungi can be used to produce material of nutritive value such as vitamins, amino acids, and lipids to make it more nutritious and palatable. Mushrooms are cultivated to yield fruit bodies directly consumed as food and yeast cells, mold mycelium is grown in fermenters to produce single-cell protein which may be used as food.

### **3.4 Plant response to AM Fungal inoculation**

Soil phosphorus is a critical factor in plant response and responses are generally better under low phosphorus levels. Host genotypes and fungal strains seem to influence the response of plants to inoculation. The worldwide field experiment has provided evidence to show that under marginal P-deficiency soils lacking in effective AM fungal endophytes increase in yield of wheat, maize, barley, potatoes, and cowpea. Increased uptake of zinc has also been shown in AM fungus inoculated peach, maize, wheat and potato in zinc deficiency soils. The AM associations related to increased uptake of sulfur and calcium, improved water absorption and tolerance of plants to water stress in citrus and avocado seedlings have also been noticed. There are also reports of increased levels of cytokinins and chlorophyll by AM fungus- infected plants [26]. Therefore, many researchers were trying to use alternative approaches based on either manipulating or adding microorganisms to enhance plant protection against pathogens. The useful microorganisms (antagonistic bacteria) (e.g., bacteria genus visible radiation, *Bacilli subtilis*) and fungi (e.g., AMF, Trichoderma) contend with plant pathogens for nutrients and house, by manufacturing antibiotics, by parasitizing pathogens [27].

### **3.5 Exploitation of AM fungi for nutrient uptake and exchange**

The fungi form a symbiotic association with roots of higher plants, facilitating uptake of plant nutrients, particularly of those which are less mobile this association is known as mycorrhizal association [28].

There are two types of mycorrhizal association (i) Ectotrophic mycorrhizae and (ii) Endomycorrhizae.

### i.Ectotrophic mycorrhizae

Ectotrophic mycorrhizae, where the fungus forms a mantle or sheath around the root surface and where the mycelium develops intracellularly. The fungi which forms this types of association are species of *Boletus, Amenita*, etc.

### ii.Endomycorrhizae

Endomycorrhizae, where the fungus develops intracellularly in the root without forming Hartig net. In this association the penetration of roots cells is characterized by the formation of terminal spherical structure called vesicular, which contain oil droplets and phosphorus. This type of mycorrhiza is called vesicular arbuscular mycorrhizae.

The management of AM fungi is very vital for organic and low-input agriculture systems wherever soil phosphorus is, in general, low, although all agroecosystems can benefit by promoting arbuscular mycorrhizae establishment. Some crops that poor at seeking out nutrients within the soil passionate about AM fungi for phosphorus uptake. For example, flax, which has poor chemotaxis ability, is highly dependent on AM-mediated phosphorus uptake at low and intermediate soil phosphorus concentrations. Proper management of AMF in the agroecosystems can improve the quality of the soil and the productivity of the land. Agricultural practices like reduced tillage, low phosphorus fertilizer usage and perennialized cropping systems promote functional mycorrhizal symbiosis [29].

### **3.6 Function of AM fungi in soil quality and phytoremediation**

The use of arbuscular mycorrhizal fungi in ecological restoration comes (phytoremediation) has been shown to modify host plant institution on degraded soil and improve soil quality and health. There is evidence to suggest that this enhancement of soil aggregated stability is due to the production of a soil protein known as glomalin [30]. The arbuscular mycorrhizal fungi and is of agricultural significance particularly in the Phosphorus deficient soils where the where the phosphorus in the vesicle diffuses out into the cytoplasm and is taken up by the plant. Fungi belonging to the genera *Glomus, Endogene* form this association [31].

### **3.7 Role of AM fungi in salinity problem**

The mycorrhizas can be used to help plants overcome extreme environmental conditions, such as saline environments [32] and several AM species have been found living in saline habitats [33]. According to some estimates, around 50% of plants living near shorelines possess mycorrhizal associations in their root systems [34]. Similarly, several species of AM were discovered in salt marsh plants [35]. Even in very saline sites reaching more than 150 dS/m of electrical conductivity, there are species of AM that can survive such hostile conditions [36].

There are different mechanisms by which AM fungi can help plants cope with salt stress. For example, they can enhance soil nutrient absorption by plants [37, 38] showed that the addition of AM fungi to lettuce and onion plants resulted in increased accumulation of phosphorus under conditions of salinity stress. Furthermore, AM can affect the ionic balance of plants, especially about Na+ and Cl<sup>−</sup> [39].

Furthermore, the addition of AM to tomato (*Lycopersicon esculentum*) under conditions of salinity improved anti-oxidant enzyme production, thus protecting cell membranes from damage. AM fungi can also improve the secretion of different types of hormones, one of them being abscisic acid. Mycorrhizal effects on hormones are important, as these hormones can enable plants to overcome many environmental stressed [40]. For example, inoculation of lettuce (*Lactuca sativa*) with Glomus intraradices induced enhanced levels of hormones in these plants under conditions of salinity stress and this, in turn, affected the regulation of stomatal closure. Salinity may also induce drought conditions for plants, so AM fungi may also help plants increase water uptake. The addition of mycorrhizas to leek (*Allium porrum*) increased the surface area of the roots, thereby increasing water absorption by the plants. The efficiency of water use in lettuce plants improved significantly with the addition of mycorrhizas under salt stress [41].

### **3.8 Potential of AM fungi in drought condition**

Rice is mostly cultivated under rain-fed conditions. The yield can be severely reduced when the water supply is insufficient, therefore drought is one of the major

**95**

*Role of Fungi in Agriculture*

numerous plants [42].

**Table 3.** *Mycoinsecticide.*

**3.9 Mycoinsecticides**

**3.10 Myconematicides**

R (*Arthrobotrys suporba*).

*DOI: http://dx.doi.org/10.5772/intechopen.89718*

constraints for rice production. Rice has its mechanisms to drought stress, and they are also assisted by living soil organisms. Arbuscular mycorrhizal (AM) fungi are among one of the soil microorganisms that may enhance drought resistance of rice. It assists plants in uptake water and nutrients. It also plays roles in regulating plant hormones, as well as stomatal behavior under drought stress. Apart from that, intercropping is likely contributing to the improvement of drought resistance and AM fungi activity. Intercropping can enhance AM fungi colonization and improve the root morphology of rice which beneficial for drought resistance. Thus, this analysis aims to achieve a lot of insight regarding the mutuality between AM fungi and rice beneath drought stress. The study will focus on the effects of AM fungi on the growth of rice, rice hormones, water potential and the contribution of AM fungi and intercropping on drought resistance of rice. The mycorrhizal development still strongly stimulated the improvement of plant growth and increased plant survival under drought stress. AMF had shown to reinforce drought tolerance in

The fungi have been utilized for controlling insect pests. The microbial control of insect pests emerged 100 years ago. Insect is infected by fungi through the body surface and this property is different from the infection caused by bacteria, viruses, and protozoa. Fungi attacking insect are called entomogenous. The conidia of the insect attacking fungi are attached to the insect integument where they germinate and the germ tubes penetrate in insect body under optimum temperature and humidity. The fungus proliferates in the insect body and the insect body gets covered with mycelia and conidia. The newly formed conidia are dispersed and cause

Based on the nature of fungal biocontrol agents the nematopathogenic fungi are of three types, nematode, trapping fungi (*Arthrobotrys, Dactylella*), endoparasites (*Hirsutella, Meria*) and highly specific egg parasites (*Datylella*). The common and commercialized myconematicide are Royal 300 R (*Arthrobotrys robata*), Royal 350

subsequent infections and the cycle is continued (**Table 3**).


### **Table 3.**

*Biostimulants in Plant Science*

symbiosis [29].

agroecosystems can benefit by promoting arbuscular mycorrhizae establishment. Some crops that poor at seeking out nutrients within the soil passionate about AM fungi for phosphorus uptake. For example, flax, which has poor chemotaxis ability, is highly dependent on AM-mediated phosphorus uptake at low and intermediate soil phosphorus concentrations. Proper management of AMF in the agroecosystems can improve the quality of the soil and the productivity of the land. Agricultural practices like reduced tillage, low phosphorus fertilizer usage and perennialized cropping systems promote functional mycorrhizal

The use of arbuscular mycorrhizal fungi in ecological restoration comes (phytoremediation) has been shown to modify host plant institution on degraded soil and improve soil quality and health. There is evidence to suggest that this enhancement of soil aggregated stability is due to the production of a soil protein known as glomalin [30]. The arbuscular mycorrhizal fungi and is of agricultural significance particularly in the Phosphorus deficient soils where the where the phosphorus in the vesicle diffuses out into the cytoplasm and is taken up by the plant. Fungi belonging

The mycorrhizas can be used to help plants overcome extreme environmental conditions, such as saline environments [32] and several AM species have been found living in saline habitats [33]. According to some estimates, around 50% of plants living near shorelines possess mycorrhizal associations in their root systems [34]. Similarly, several species of AM were discovered in salt marsh plants [35]. Even in very saline sites reaching more than 150 dS/m of electrical conductivity,

There are different mechanisms by which AM fungi can help plants cope with salt stress. For example, they can enhance soil nutrient absorption by plants [37, 38] showed that the addition of AM fungi to lettuce and onion plants resulted in increased accumulation of phosphorus under conditions of salinity stress. Furthermore, AM can

Furthermore, the addition of AM to tomato (*Lycopersicon esculentum*) under conditions of salinity improved anti-oxidant enzyme production, thus protecting cell membranes from damage. AM fungi can also improve the secretion of different types of hormones, one of them being abscisic acid. Mycorrhizal effects on hormones are important, as these hormones can enable plants to overcome many environmental stressed [40]. For example, inoculation of lettuce (*Lactuca sativa*) with Glomus intraradices induced enhanced levels of hormones in these plants under conditions of salinity stress and this, in turn, affected the regulation of stomatal closure. Salinity may also induce drought conditions for plants, so AM fungi may also help plants increase water uptake. The addition of mycorrhizas to leek (*Allium porrum*) increased the surface area of the roots, thereby increasing water absorption by the plants. The efficiency of water use in lettuce plants improved significantly

Rice is mostly cultivated under rain-fed conditions. The yield can be severely reduced when the water supply is insufficient, therefore drought is one of the major

and Cl<sup>−</sup> [39].

**3.6 Function of AM fungi in soil quality and phytoremediation**

to the genera *Glomus, Endogene* form this association [31].

there are species of AM that can survive such hostile conditions [36].

affect the ionic balance of plants, especially about Na+

with the addition of mycorrhizas under salt stress [41].

**3.8 Potential of AM fungi in drought condition**

**3.7 Role of AM fungi in salinity problem**

**94**

*Mycoinsecticide.*

constraints for rice production. Rice has its mechanisms to drought stress, and they are also assisted by living soil organisms. Arbuscular mycorrhizal (AM) fungi are among one of the soil microorganisms that may enhance drought resistance of rice. It assists plants in uptake water and nutrients. It also plays roles in regulating plant hormones, as well as stomatal behavior under drought stress. Apart from that, intercropping is likely contributing to the improvement of drought resistance and AM fungi activity. Intercropping can enhance AM fungi colonization and improve the root morphology of rice which beneficial for drought resistance. Thus, this analysis aims to achieve a lot of insight regarding the mutuality between AM fungi and rice beneath drought stress. The study will focus on the effects of AM fungi on the growth of rice, rice hormones, water potential and the contribution of AM fungi and intercropping on drought resistance of rice. The mycorrhizal development still strongly stimulated the improvement of plant growth and increased plant survival under drought stress. AMF had shown to reinforce drought tolerance in numerous plants [42].

### **3.9 Mycoinsecticides**

The fungi have been utilized for controlling insect pests. The microbial control of insect pests emerged 100 years ago. Insect is infected by fungi through the body surface and this property is different from the infection caused by bacteria, viruses, and protozoa. Fungi attacking insect are called entomogenous. The conidia of the insect attacking fungi are attached to the insect integument where they germinate and the germ tubes penetrate in insect body under optimum temperature and humidity. The fungus proliferates in the insect body and the insect body gets covered with mycelia and conidia. The newly formed conidia are dispersed and cause subsequent infections and the cycle is continued (**Table 3**).

### **3.10 Myconematicides**

Based on the nature of fungal biocontrol agents the nematopathogenic fungi are of three types, nematode, trapping fungi (*Arthrobotrys, Dactylella*), endoparasites (*Hirsutella, Meria*) and highly specific egg parasites (*Datylella*). The common and commercialized myconematicide are Royal 300 R (*Arthrobotrys robata*), Royal 350 R (*Arthrobotrys suporba*).

### **4. Conclusions**

The increased absorption of available nutrients from soil as the fungus changes root morphology, which result in the larger root surface available for nutrient absorption. Fungal filaments also act as the absorption surface and increasing the nutrient availability by solubilizing insoluble nutrients like phosphorus, which thus become available to plant and increasing the nutrient mobility due to faster intracellular nutrient mobility and mobilizing nutrients from the soil mass not visited by the roots system but traversed by the mycorrhizal hyphae. The arbuscular mycorrhizal fungi protected plants by up-regulating the activity of antioxidant enzymes and osmolytes and by regulating the synthesis of phytohormones, which might possibly interconnect the various tolerance mechanisms for cumulative stress response. The prominent effect of arbuscular mycorrhizal fungi against salinity was proven to be due to a restriction in sodium uptake by roots and to the homeostasis of nutrient uptake.

### **Author details**

Muthuraman Yuvaraj\* and Murugaragavan Ramasamy Department of Soil Science and Agricultural College, Adhiparasakthi Agricultural College, Tamil Nadu, India

\*Address all correspondence to: yuvasoil@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.

**97**

*Role of Fungi in Agriculture*

India: Springer; 2005

Education; 2009

Natural Resources; 2008

[4] Metting FB. Structure and

Inc.: New York. 1993; pp. 3-25

[5] Sylvia DM, Hartel PG,

Prentice Hall; 2005

2013;**51**(6):850-857

2013;**23**(6):856-863

**References**

*DOI: http://dx.doi.org/10.5772/intechopen.89718*

[1] Lavelle P, Spain AV. Soil Ecology and Chapter 3: Soil Organisms. New Delhi,

[9] Radhakrishnan R, Kang SM,

Baek IY, Lee IJ. Characterization of plant growth-promoting traits of *Penicillium* species against the effects of high soil salinity and root disease. Journal of Plant Interactions. 2014;**9**(1):754-762

[10] Sreenivasa MN, Bagyaraj DJ. Use of pesticides for mass production of vesicular arbuscular mycorrhizal

[11] Smith SE Read DJ. Mycorrhizal Symbiosis. 2nd ed. London, UK: Academic Press; 1997. p. 605

[12] Smith SE, Read DJ. Mycorrhizal Symbiosis. 3rd ed. London: Academic

[13] Sturz AV, Carter MR, Johnston HW. A review of plant disease, pathogen interactions and microbial antagonism under conservation tillage in temperate humid agriculture. Soil and Tillage

[14] Waqas M, Khan AL, Lee IJ. Bioactive chemical constituents produced by endophytes and effects on rice plant growth. Journal of Plant Interactions.

[15] Seastedt TR, Hobbs RJ, Suding KN. Management of novel ecosystems are novel approaches required? Frontiers in Ecology and the Environment.

Gonzales HHS, Floh EIS, Barbosa HR.

enterobacteria isolated from sugar cane have different potentials for producing plant growth-promoting substances. Plant and Soil. 2012;**353**:409-417

Barea JM, Haselwandter K. Mycorrhizal Technology in Agriculture: From Genes

[16] Ferrara FIS, Oliveira ZM,

Endophytic and rhizospheric

[17] Gianinazzi S, Schuepp H,

inoculum. Plant and Soil.

1989;**119**:127-132

Press; 2008. p. 800

Research. 1997;**41**:169-189

2014;**9**:478-487

2008;**6**:547-553

[2] Magdoff F, Van H. Building Soils for Better Soil: Sustainable Soil Management, Chapter 4: The Living Soil. In: Sustainable Agriculture Network, Handbook Series Book 10. 3rd ed. Beltsville, Maryland: SARE Sustainable Agriculture Research &

[3] Islam KR. Lecture on Soil Physics, Personal Collection of R. Islam. Columbus, OH: The Ohio State

University School of Environment and

physiological ecology of soil microbial communities. n F.B. Metting, Jr. (Ed.), Soil Microbial Ecology, Marcel Dekker,

Fuhrmann JJ, Zuberer DA. In: Sylva DM, editor. Principles and Applications of Soil Microbiology (2nd Ed.). Upper Saddle River, New Jersey: Pearson

[6] Lowenfels J, Lewis W. Teaming with Microbes A gardener's Guide to the Soil Food Web, Chapter 3: Bacteria. Portland, Oregon: Timber Press; 2006

[7] Radhakrishnan R, Khan AL, Lee IJ. Endophytic fungal pre-treatments to seeds alleviate salinity stress effects in soybean plants. Journal of Microbiology.

[8] Radhakrishnan R, Shim KB, Lee BW, Hwang CD, Pae SB, Park CH, et al. IAA producing *Penicillium* sp. NICS01 triggers plant growth and suppresses fusarium induced oxidative stress in sesame (*Sesamum indicum* L.). Journal of Microbiology and Biotechnology.

### **References**

*Biostimulants in Plant Science*

The increased absorption of available nutrients from soil as the fungus changes

root morphology, which result in the larger root surface available for nutrient absorption. Fungal filaments also act as the absorption surface and increasing the nutrient availability by solubilizing insoluble nutrients like phosphorus, which thus become available to plant and increasing the nutrient mobility due to faster intracellular nutrient mobility and mobilizing nutrients from the soil mass not visited by the roots system but traversed by the mycorrhizal hyphae. The arbuscular mycorrhizal fungi protected plants by up-regulating the activity of antioxidant enzymes and osmolytes and by regulating the synthesis of phytohormones, which might possibly interconnect the various tolerance mechanisms for cumulative stress response. The prominent effect of arbuscular mycorrhizal fungi against salinity was proven to be due to a restriction in sodium uptake by roots and to the homeostasis of

**4. Conclusions**

nutrient uptake.

**Author details**

College, Tamil Nadu, India

Muthuraman Yuvaraj\* and Murugaragavan Ramasamy

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

provided the original work is properly cited.

Department of Soil Science and Agricultural College, Adhiparasakthi Agricultural

© 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,

**96**

[1] Lavelle P, Spain AV. Soil Ecology and Chapter 3: Soil Organisms. New Delhi, India: Springer; 2005

[2] Magdoff F, Van H. Building Soils for Better Soil: Sustainable Soil Management, Chapter 4: The Living Soil. In: Sustainable Agriculture Network, Handbook Series Book 10. 3rd ed. Beltsville, Maryland: SARE Sustainable Agriculture Research & Education; 2009

[3] Islam KR. Lecture on Soil Physics, Personal Collection of R. Islam. Columbus, OH: The Ohio State University School of Environment and Natural Resources; 2008

[4] Metting FB. Structure and physiological ecology of soil microbial communities. n F.B. Metting, Jr. (Ed.), Soil Microbial Ecology, Marcel Dekker, Inc.: New York. 1993; pp. 3-25

[5] Sylvia DM, Hartel PG, Fuhrmann JJ, Zuberer DA. In: Sylva DM, editor. Principles and Applications of Soil Microbiology (2nd Ed.). Upper Saddle River, New Jersey: Pearson Prentice Hall; 2005

[6] Lowenfels J, Lewis W. Teaming with Microbes A gardener's Guide to the Soil Food Web, Chapter 3: Bacteria. Portland, Oregon: Timber Press; 2006

[7] Radhakrishnan R, Khan AL, Lee IJ. Endophytic fungal pre-treatments to seeds alleviate salinity stress effects in soybean plants. Journal of Microbiology. 2013;**51**(6):850-857

[8] Radhakrishnan R, Shim KB, Lee BW, Hwang CD, Pae SB, Park CH, et al. IAA producing *Penicillium* sp. NICS01 triggers plant growth and suppresses fusarium induced oxidative stress in sesame (*Sesamum indicum* L.). Journal of Microbiology and Biotechnology. 2013;**23**(6):856-863

[9] Radhakrishnan R, Kang SM, Baek IY, Lee IJ. Characterization of plant growth-promoting traits of *Penicillium* species against the effects of high soil salinity and root disease. Journal of Plant Interactions. 2014;**9**(1):754-762

[10] Sreenivasa MN, Bagyaraj DJ. Use of pesticides for mass production of vesicular arbuscular mycorrhizal inoculum. Plant and Soil. 1989;**119**:127-132

[11] Smith SE Read DJ. Mycorrhizal Symbiosis. 2nd ed. London, UK: Academic Press; 1997. p. 605

[12] Smith SE, Read DJ. Mycorrhizal Symbiosis. 3rd ed. London: Academic Press; 2008. p. 800

[13] Sturz AV, Carter MR, Johnston HW. A review of plant disease, pathogen interactions and microbial antagonism under conservation tillage in temperate humid agriculture. Soil and Tillage Research. 1997;**41**:169-189

[14] Waqas M, Khan AL, Lee IJ. Bioactive chemical constituents produced by endophytes and effects on rice plant growth. Journal of Plant Interactions. 2014;**9**:478-487

[15] Seastedt TR, Hobbs RJ, Suding KN. Management of novel ecosystems are novel approaches required? Frontiers in Ecology and the Environment. 2008;**6**:547-553

[16] Ferrara FIS, Oliveira ZM, Gonzales HHS, Floh EIS, Barbosa HR. Endophytic and rhizospheric enterobacteria isolated from sugar cane have different potentials for producing plant growth-promoting substances. Plant and Soil. 2012;**353**:409-417

[17] Gianinazzi S, Schuepp H, Barea JM, Haselwandter K. Mycorrhizal Technology in Agriculture: From Genes

to Biproducts. Switzerland: Springer; 2002

[18] Maeder P, Fliessbach A, Dubois D, Gunst L, Fried P, Niggli U. Soil fertility and biodiversity in organic farming. Science. 2002;**296**:1694-1697

[19] Gianinazzi S, Bosatka M. Inoculum of arbuscular mycorrhizal fungi for production systems: Science meets business. Canadian Journal of Botany. 2004;**82**:64-71

[20] Alqarawi AA, Abdallah EF, Hashem A. Alleviation of salt-induced adverse impact via mycorrhizal fungi in *Ephedra aphylla* Forssk. Journal of Plant Interactions. 2014;**9**(1):802-810

[21] Mo Y, Wang Y, Yang R, Zheng J, Liu C, Li H, et al. Regulation of plant growth, photosynthesis, antioxidation and osmosis by an arbuscular mycorrhizal fungus in watermelon seedlings under well-watered and drought conditions. Frontiers in Plant Science. 2016;**7**:644

[22] Hashem A, Abdaallah EF, Alqarawi AA, Aldubise A, Egamberdieva D. Arbuscular mycorrhizal fungi enhances salinity tolerance of *Panicum turgidum* Forssk by altering photosynthetic and antioxidant pathways. Journal of Plant Interactions. 2015;**10**(1):230-242

[23] Shekoofeh E, Sepideh H, Roya R. Role of mycorrhizal fungi and salicylic acid in salinity tolerance of *Ocimum basilicum* resistance to salinity. Journal of Biotechnology. 2012;**11**(9):2223-2235

[24] Balliu A, Sallaku G, Rewald B. AMF inoculation enhances growth and improves the nutrient uptake rates of transplanted, salt-stressed tomato seedlings. Sustainability. 2015;**7**:15967-15981

[25] Jones MD, Smith SE. Exploring functional definitions of mycorrhizas are mycorrhizas always mutualisms? Canadian Journal of Botany. 2004;**82**:1089-1109

[26] Landis FC, Gargas A, Givnish TJ. Relationships among arbuscular mycorrhizal fungi, vascular plants and environmental conditions in oak savannas. The New Phytologist. 2004;**164**:493-504

[27] Tarafdar JC, Marschner H. Efficiency of VAM hyphae in utilization of organic phosphorus by wheat plants. Soil Science & Plant Nutrition. 1994;**40**:593-600

[28] Clark RB, Zeto SK. Mineral acquisition by arbuscular mycorrhizal plants. Journal of Plant Nutrition. 2000;**23**:867-902

[29] Hildebrandt U, Janetta K, Ouziad F, Renne B, Nawrath K, Bothe H. Arbuscular mycorrhizal colonization of halophytes in central European salt marshes. Mycorrhiza. 2001;**10**:175-183

[30] Liu R, Wang F. Selection of appropriate host plants used in trap culture of arbuscular mycorrhizal fungi. Mycorrhiza. 2003;**13**:123-127

[31] Cooke JC, Lefor MW. The mycorrhizal status of selected plant species from Connecticut wetlands and transition zones. Restoration Ecology. 1998;**6**:214-222

[32] Aliasgharzadeh N, Rastin SN, Towfighi H, Alizadeh A. Occurrence of arbuscular mycorrhizal fungi in saline soils of the Tabriz Plain of Iran in relation to some physical and chemical properties of soil. Mycorrhiza. 2001;**11**:119-122

[33] Asghari HR, Marschner P, Smith SE, Smith FA. Growth response of *Atriplex nummularia* to inoculation with arbuscular mycorrhizal fungi at different salinity levels. Plant and Soil. 2005;**273**:245-256

**99**

2002;**11**:2669-2678

*Role of Fungi in Agriculture*

and Soil. 2001:269-281

2007;**54**:753-760

*DOI: http://dx.doi.org/10.5772/intechopen.89718*

arbuscular mycorrhizal fungi during old-field succession. Oecologia.

[42] Berg G, Smalla K. Plant species and soil type cooperatively shape the structure and function of microbial communities in the rhizosphere. FEMS Microbiology Ecology. 2009;**68**:1-13

[43] Hodge A, Campbell CD, Fitter AH, et al. An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic matter.

[44] Wells JM, Boddy L, Donnelly DP.

Nature. 2001;**413**:297-299

1998;**138**:607-617

2010;**113**:163-169

2012;**15**:1042-1049

University; 2011

Wood decay and phosphorus translocation by the cord forming basidiomycete *Phanerochaete velutina*: The significance of local nutrient supply. The New Phytologist.

[45] Cohen R, Persky L, Hadar Y. Biotechnological applications and potential of wood-degrading mushrooms of the genus Pleurotus.

[46] Chaverri P, Gazis RO. *Perisporiopsis lateritia*, a new species on decaying leaves of *Hevea* spp. from the Amazon basin in Peru. Mycotaxon.

[47] Phillips RP, Meier IC, Bernhardt ES, Grandy S, Wickings K, Finzi AC. Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO2. Ecology Letters.

[48] Hoorman JJ. The Role of Soil Fungus (report no. SAG-14-11). Columbus, Ohio, USA: Ohio State

[49] Yaseen T, Burni T, Hussain F. Effect of Arbuscular mycorrhizal inoculation on nutrient uptake, growth and productivity of cowpea (*Vigna* 

Applied Microbiology and Biotechnology. 2002;**58**:582-594

1991;**86**:49-58

[34] Cantrell IC, Linderman RG. Pre inoculation of lettuce and onion with VA mycorrhizal fungi reduces deleterious effects of soil salinity. Plant

[35] Giri B, Kapoor R, Mukerji KG. Improved tolerance of Acacia nilotica to salt stress by arbuscular mycorrhiza, *Glomus fasciculatum* may be partly related to elevated K/Na ratios in root and shoot tissues. Microbial Ecology*.*

[36] Zhang YF, Wang P, Yang YF, Bi Q, Tian SY, Shi XW. Arbuscular

reestablishment of *Leymus chinensis* in bare saline alkaline soil: Implication on vegetation restoration of extremely

mycorrhizal fungi improve

degraded land. Journal of Arid Enviroments. 2011;**75**:773-778

[37] Jahromi F, Aroca R, Porcel R, Ruiz-Lozano JM. Influence of salinity on the in vitro development of *Glomus intraradices* and on the in vivo physiological and molecular responses of mycorrhizal lettuce plants. Microbial

Ecology. 2008;**55**:45-53

[38] Ruiz-Lozano JM, Azcon R, Gomez M. Alleviation of salt stress by arbuscular mycorrhizal *Glomus* species in *Lactuca sativa* plant. Physiologia Plantarum. 1996;**98**:767-772

[39] Garg N, Manchanda G. Role of arbuscular mycorrhizae in the alleviation of ionic, osmotic and oxidative stresses induced by salinity in *Cajanus cajan* (L.) Millsp. (pigeonpea). Journal of Agronomy and Crop Science. 2009;**195**:110-115

[40] Husband R, Herre EA, Turner SL. Molecular diversity of arbuscular mycorrhizal fungi and patterns of host association over time and space in a tropical forest. Molecular Ecology.

[41] Johnson NC, Zak DR, Tilman D, Pfleger DL. Dynamics of vesicular

### *Role of Fungi in Agriculture DOI: http://dx.doi.org/10.5772/intechopen.89718*

*Biostimulants in Plant Science*

2002

to Biproducts. Switzerland: Springer;

are mycorrhizas always mutualisms?

[26] Landis FC, Gargas A, Givnish TJ. Relationships among arbuscular mycorrhizal fungi, vascular plants and environmental conditions in oak savannas. The New Phytologist.

Canadian Journal of Botany.

[27] Tarafdar JC, Marschner H.

of organic phosphorus by wheat plants. Soil Science & Plant Nutrition.

[28] Clark RB, Zeto SK. Mineral acquisition by arbuscular mycorrhizal plants. Journal of Plant Nutrition.

Renne B, Nawrath K, Bothe H. Arbuscular mycorrhizal colonization of halophytes in central European salt marshes. Mycorrhiza. 2001;**10**:175-183

[30] Liu R, Wang F. Selection of appropriate host plants used in trap culture of arbuscular mycorrhizal fungi.

Mycorrhiza. 2003;**13**:123-127

[31] Cooke JC, Lefor MW. The mycorrhizal status of selected plant species from Connecticut wetlands and transition zones. Restoration Ecology.

[32] Aliasgharzadeh N, Rastin SN, Towfighi H, Alizadeh A. Occurrence of arbuscular mycorrhizal fungi in saline soils of the Tabriz Plain of Iran in relation to some physical and chemical properties of soil. Mycorrhiza.

[33] Asghari HR, Marschner P,

Smith SE, Smith FA. Growth response of *Atriplex nummularia* to inoculation with arbuscular mycorrhizal fungi at different salinity levels. Plant and Soil.

1998;**6**:214-222

2001;**11**:119-122

2005;**273**:245-256

Efficiency of VAM hyphae in utilization

[29] Hildebrandt U, Janetta K, Ouziad F,

2004;**82**:1089-1109

2004;**164**:493-504

1994;**40**:593-600

2000;**23**:867-902

[18] Maeder P, Fliessbach A, Dubois D, Gunst L, Fried P, Niggli U. Soil fertility and biodiversity in organic farming.

[19] Gianinazzi S, Bosatka M. Inoculum of arbuscular mycorrhizal fungi for production systems: Science meets business. Canadian Journal of Botany.

Science. 2002;**296**:1694-1697

[20] Alqarawi AA, Abdallah EF, Hashem A. Alleviation of salt-induced adverse impact via mycorrhizal fungi in *Ephedra aphylla* Forssk. Journal of Plant

Interactions. 2014;**9**(1):802-810

and osmosis by an arbuscular mycorrhizal fungus in watermelon seedlings under well-watered and drought conditions. Frontiers in Plant

[22] Hashem A, Abdaallah EF, Alqarawi AA, Aldubise A,

Egamberdieva D. Arbuscular mycorrhizal fungi enhances salinity tolerance of *Panicum turgidum* Forssk by altering photosynthetic and antioxidant

pathways. Journal of Plant Interactions.

[23] Shekoofeh E, Sepideh H, Roya R. Role of mycorrhizal fungi and salicylic acid in salinity tolerance of *Ocimum basilicum* resistance to salinity. Journal of Biotechnology. 2012;**11**(9):2223-2235

[24] Balliu A, Sallaku G, Rewald B. AMF inoculation enhances growth and improves the nutrient uptake rates of transplanted, salt-stressed tomato seedlings. Sustainability.

[25] Jones MD, Smith SE. Exploring functional definitions of mycorrhizas

Science. 2016;**7**:644

2015;**10**(1):230-242

2015;**7**:15967-15981

[21] Mo Y, Wang Y, Yang R, Zheng J, Liu C, Li H, et al. Regulation of plant growth, photosynthesis, antioxidation

2004;**82**:64-71

**98**

[34] Cantrell IC, Linderman RG. Pre inoculation of lettuce and onion with VA mycorrhizal fungi reduces deleterious effects of soil salinity. Plant and Soil. 2001:269-281

[35] Giri B, Kapoor R, Mukerji KG. Improved tolerance of Acacia nilotica to salt stress by arbuscular mycorrhiza, *Glomus fasciculatum* may be partly related to elevated K/Na ratios in root and shoot tissues. Microbial Ecology*.* 2007;**54**:753-760

[36] Zhang YF, Wang P, Yang YF, Bi Q, Tian SY, Shi XW. Arbuscular mycorrhizal fungi improve reestablishment of *Leymus chinensis* in bare saline alkaline soil: Implication on vegetation restoration of extremely degraded land. Journal of Arid Enviroments. 2011;**75**:773-778

[37] Jahromi F, Aroca R, Porcel R, Ruiz-Lozano JM. Influence of salinity on the in vitro development of *Glomus intraradices* and on the in vivo physiological and molecular responses of mycorrhizal lettuce plants. Microbial Ecology. 2008;**55**:45-53

[38] Ruiz-Lozano JM, Azcon R, Gomez M. Alleviation of salt stress by arbuscular mycorrhizal *Glomus* species in *Lactuca sativa* plant. Physiologia Plantarum. 1996;**98**:767-772

[39] Garg N, Manchanda G. Role of arbuscular mycorrhizae in the alleviation of ionic, osmotic and oxidative stresses induced by salinity in *Cajanus cajan* (L.) Millsp. (pigeonpea). Journal of Agronomy and Crop Science. 2009;**195**:110-115

[40] Husband R, Herre EA, Turner SL. Molecular diversity of arbuscular mycorrhizal fungi and patterns of host association over time and space in a tropical forest. Molecular Ecology. 2002;**11**:2669-2678

[41] Johnson NC, Zak DR, Tilman D, Pfleger DL. Dynamics of vesicular

arbuscular mycorrhizal fungi during old-field succession. Oecologia. 1991;**86**:49-58

[42] Berg G, Smalla K. Plant species and soil type cooperatively shape the structure and function of microbial communities in the rhizosphere. FEMS Microbiology Ecology. 2009;**68**:1-13

[43] Hodge A, Campbell CD, Fitter AH, et al. An arbuscular mycorrhizal fungus accelerates decomposition and acquires nitrogen directly from organic matter. Nature. 2001;**413**:297-299

[44] Wells JM, Boddy L, Donnelly DP. Wood decay and phosphorus translocation by the cord forming basidiomycete *Phanerochaete velutina*: The significance of local nutrient supply. The New Phytologist. 1998;**138**:607-617

[45] Cohen R, Persky L, Hadar Y. Biotechnological applications and potential of wood-degrading mushrooms of the genus Pleurotus. Applied Microbiology and Biotechnology. 2002;**58**:582-594

[46] Chaverri P, Gazis RO. *Perisporiopsis lateritia*, a new species on decaying leaves of *Hevea* spp. from the Amazon basin in Peru. Mycotaxon. 2010;**113**:163-169

[47] Phillips RP, Meier IC, Bernhardt ES, Grandy S, Wickings K, Finzi AC. Roots and fungi accelerate carbon and nitrogen cycling in forests exposed to elevated CO2. Ecology Letters. 2012;**15**:1042-1049

[48] Hoorman JJ. The Role of Soil Fungus (report no. SAG-14-11). Columbus, Ohio, USA: Ohio State University; 2011

[49] Yaseen T, Burni T, Hussain F. Effect of Arbuscular mycorrhizal inoculation on nutrient uptake, growth and productivity of cowpea (*Vigna* 

*unguiculata*) varieties. African Journal of Biotechnology. 2011;**10**: 8593-8598

[50] Albrechtova J, Latr A, Nedorost L, Pokluda R, Posta K, Vosatka M. Dual inoculation with mycorrhizal and saprotrophic fungi applicable in sustainable cultivation improves the yield and nutritive value of onion. Scientific World Journal. 2012:1-8

[51] Contreras-Cornejo HA, Macias-Rodriguez L, Cortes-Penagos C, Lopez-Bucio J. *Trichoderma virens*, a plant beneficial fungus, enhances biomass production and promotes lateral root growth through an auxindependent mechanism in Arabidopsis. American Society of Plant Biologists. 2009;**149**:1579-1592

[52] Chalot M, Brun A. Physiology of organic nitrogen acquisition by ectomycorrhizal fungi and ectomycorrhizas. FEMS Microbiology Reviews. 1998;**22**:21-44

[53] Harman G, Mastouri F. The role of Trichoderma in crop management systems. Phytopathology. 2010;**100**:16

[54] Ha TN. Using *Trichoderma* species for biological control of plant pathogens in Vietnam. Journal of ISSAAS. 2010;**16**:17-21

[55] Arnold AE, Engelbrecht BMJ. Fungal endophytes nearly double minimum leaf conductance in seedlings of a neotropical tree species. Journal of Tropical Ecology. 2007;**23**:369-372

**101**

**Chapter 7**

**Abstract**

the mycorrhizosphere.

**1. Introduction**

Arbuscular Mycorrhiza-Associated

Rhizobacteria and Biocontrol of

*Devendra Kumar Srivastava and Pradeep Kumar Singh*

**Keywords:** AM-associated bacteria (AMB), arbuscular mycorrhizal fungi,

[3, 4], AM fungi form widespread mycelial networks within the soil atmosphere, and hyphae harbour important sites for interactions with other soilborne microorganisms. The constricted zone adjacent to soil-living roots is called the

A majority of land plants in nature are growing symbiotically in relationship with AM fungi. This relationship is well established with the roots of these plants. Soil exploration by the external mycelium of AM fungi increases the nutrient absorptive root surface area and thus favors the host plant in access to nutrients and water [1, 2]. Moreover, as the largest component of the soil microbial biomass

biocontrol, mycorrhizosphere, soilborne pathogens

The mutualistic symbiosis of most land plants with arbuscular mycorrhizal (AM) fungi has been shown to favor mineral and water nutrition and to increase resistance to abiotic and biotic stresses. The main mechanisms involved in the control of the disease symptoms and intraradical proliferation of soilborne phytopathogens are due to root colonization with AM fungi. The role of the rhizobacteria is shown to be specifically associated with extraradical network of the AM and mycorrhizosphere. The mycorrhizosphere can form a favorable environment for microorganisms which have potentiality to act antagonistic to pathogen abundance. It makes an additional advantage in identifying rhizobacteria from AM fungi structures or mycorrhizosphere, which often lead to the isolation of organisms having strong properties of antagonism on various soilborne pathogens. The ability of AM fungi to control soilborne diseases is mainly related to their capacity to stimulate the establishment of rhizobacteria against the favorable environment of pathogen within the mycorrhizosphere prior to the root infection. Recent advancement in scientific research has provided more clear picture in understanding the mechanisms involved in AM fungi/rhizobacteria interactions. Herein, this chapter includes the mechanisms of the AM fungi-mediated biocontrol, interactions between AM-associated bacteria and AM fungus extraradical network, AM-associated bacteria and biocontrol activities and unfavorable zone to pathogen development:

Soilborne Phytopathogens

*Meenakshi Singh, Manjari Mishra,* 

### **Chapter 7**

*Biostimulants in Plant Science*

8593-8598

*unguiculata*) varieties. African Journal of Biotechnology. 2011;**10**:

[51] Contreras-Cornejo HA,

2009;**149**:1579-1592

Reviews. 1998;**22**:21-44

[50] Albrechtova J, Latr A, Nedorost L, Pokluda R, Posta K, Vosatka M. Dual inoculation with mycorrhizal and saprotrophic fungi applicable in sustainable cultivation improves the yield and nutritive value of onion. Scientific World Journal. 2012:1-8

Macias-Rodriguez L, Cortes-Penagos C, Lopez-Bucio J. *Trichoderma virens*, a plant beneficial fungus, enhances biomass production and promotes lateral root growth through an auxindependent mechanism in Arabidopsis. American Society of Plant Biologists.

[52] Chalot M, Brun A. Physiology of organic nitrogen acquisition by ectomycorrhizal fungi and

ectomycorrhizas. FEMS Microbiology

[53] Harman G, Mastouri F. The role of Trichoderma in crop management systems. Phytopathology. 2010;**100**:16

[54] Ha TN. Using *Trichoderma* species for biological control of plant pathogens

in Vietnam. Journal of ISSAAS.

[55] Arnold AE, Engelbrecht BMJ. Fungal endophytes nearly double minimum leaf conductance in seedlings of a neotropical tree species. Journal of Tropical Ecology. 2007;**23**:369-372

2010;**16**:17-21

**100**
