*4.1.7 Phyto-availability of micronutrients*

A part from the macronutrients, AM fungi association has been reported to increase the phyto-availability of micronutrients like zinc and copper. Also, it helps the plants to take up nutrients from the nutrient-deficient soils. It is also responsible for the uptake of almost all essential nutrients, specifically phosphate, in plants. It was also reported to increase the absorption of trace elements, such as boron and molybdenum [43–45].

On the other hand, it also decreases the uptake of sodium and chlorine thereby stimulating the plant growth. Increased nitrogen content in plants evidently results in higher chlorophyll contents that can effectively trap nitrogen. Maintenance of calcium ion and sodium ion ratio helps improve the overall plant performance. It also improves the surface absorbing capability of host roots [46–48].

Some examples of enhancement of mineral nutrition:


#### *4.1.8 Quality of soil*

Mycorrhizal symbiosis can be further increased by agricultural practices like reduced tillage, low phosphorus fertilizer usage, and perennialized cropping systems [59, 60]. In the agroecosystems the quality of the soil and the productivity of the land can be enhanced by colonization of AM fungi. It enhances the constant masses, soil aggregate stability, rapidity of soil recovery, and significantly increases extra-radical hyphal mycelium in the soil. This is due to a soil protein known as glomalin, that is thought to be of AM fungal origin. Glomalin is responsible for improving soil aggregate water stability and for decreasing soil erosion [61].

#### *4.1.9 Water stress tolerance*

By physiological alteration of the above-ground organs and tissues, it enhances water stress tolerance, accumulation of dry matter and water moisture uptake, thereby improving plant tolerance against stresses like salinity and drought. Glomalin-related soil protein (GRSP) is maintain water content in soils exposed to different abiotic stresses and enhances the soil water holding capacity, which later on regulates water frequencies between soil and plants, thereby enhancing plant development [62–64].

#### *4.1.10 Plant tolerance to stressful circumstances*

Plant tolerance against various biotic and abiotic stressful circumstances like alkalinity and toxicity resulting from mining operations, heavy metals and mineral imbalance are reported to be increased by AM symbiosis. This is because of the communal nutrients' relocation from fungi to the plant, along with other related effects such as changes in their morpho-physiological traits [65–72].

#### *4.1.11 Disease control*

Apart from increasing the availability of macro and micronutrients, AM provides the plant with necessary strength to resist disease germs and unfavorable conditions. They also increase host tolerance to pathogen attack and compensate for the loss of root biomass or function caused by pathogens including Root-knot nematodes and fungi [73, 74]. The presence of AM fungi showed consistent reduction of disease symptoms for fungal pathogens such as *Phytophthora, Fusarium, Chalara, Pythium, Rhizoctonia, Sclerotium, Verticillium, Aphanomyces.* Several hypotheses have been put forwarded to explain the mechanisms of plant disease control by mycorrhizal fungi [75–77].

Some of them include creating a mechanical barrier for the pathogen penetration, thickening of cell wall through lignification and polysaccharide production that stops the entry of root pathogen, stimulation of the host roots to produce and accumulate sufficient concentration of metabolites like terpenes and phenols, imparting resistance to the host tissue against pathogen invasion, stimulating flavonolic wall infusions to prevent lesion formation by the pathogen, producing antifungal and antibacterial antibiotics, competing with the pathogens for the uptake of essential nutrients in the rhizosphere and at the roots surface, competitions in the roots and thus preventing the pathogen to get access to the roots. Harboring more actinomycetes antagonistic to root pathogen [78–81].

**25**

**Author details**

Kavita Chahal1

India

and Babita Rana3

Madhya Pradesh, India

\*, Vaishali Gupta1

Commerce, Matunga, Mumbai, India

provided the original work is properly cited.

, Naveen Kumar Verma1

1 Department of Botany, Government College, Bichhua, Chhindwara,

2 Department of Botany, Government College, Pawai, Panna, Madhya Pradesh,

© 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,

3 Department of Botany, Guru Nanak Khalsa College of Arts, Science and

\*Address all correspondence to: kavitachahal18@gmail.com

, Anand Chaurasia2

*Arbuscular Mycorrhizal (AM) Fungi as a Tool for Sustainable Agricultural System*

Modern sustainable agriculture demands for a low-input and more naturebased system having role of soil loving microorganisms that are able to accelerate plant nutrition, health and soil, quality, also under stressful environments. All of these demands are being fulfilled by AM fungi. Its use in increasing food production is far and wide; therefore, is a better tool for modern sustainable agriculture particularly as biocontrol agent. Encouragement of AM as a tool for sustainable agriculture usage is of immense importance. Exploitation of AM for promoting a bio-healthy agriculture can significantly reduce the use of synthetic fertilizers and other chemicals resulting in agricultural improvement. Hence, using AM fungi as a biocontrol agent in modern sustainable agriculture, in terms of various parameters like reduction of damage caused by various pathogens, cost effectiveness, energy saving and also as an environment friendly, is a promising perspective for a sustainable agricultural system. The primary focus of future research should be on the identification of genes and gene products controlling the AMF mediated growth and development regulation under stressful cues. Identification of both host as well as AMF specific protein factors regulating symbiotic association and the major cellular and metabolic pathways under different environmental stresses can be hot

*DOI: http://dx.doi.org/10.5772/intechopen.94442*

**5. Conclusion and future prospect**

areas for future research in this field.

*Arbuscular Mycorrhizal (AM) Fungi as a Tool for Sustainable Agricultural System DOI: http://dx.doi.org/10.5772/intechopen.94442*

## **5. Conclusion and future prospect**

*Mycorrhizal Fungi - Utilization in Agriculture and Forestry*

Mycorrhizal symbiosis can be further increased by agricultural practices

By physiological alteration of the above-ground organs and tissues, it enhances water stress tolerance, accumulation of dry matter and water moisture uptake, thereby improving plant tolerance against stresses like salinity and drought. Glomalin-related soil protein (GRSP) is maintain water content in soils exposed to different abiotic stresses and enhances the soil water holding capacity, which later on regulates water frequencies between soil and plants, thereby enhancing plant

Plant tolerance against various biotic and abiotic stressful circumstances like alkalinity and toxicity resulting from mining operations, heavy metals and mineral imbalance are reported to be increased by AM symbiosis. This is because of the communal nutrients' relocation from fungi to the plant, along with other related

Apart from increasing the availability of macro and micronutrients, AM provides the plant with necessary strength to resist disease germs and unfavorable conditions. They also increase host tolerance to pathogen attack and compensate for the loss of root biomass or function caused by pathogens including Root-knot nematodes and fungi [73, 74]. The presence of AM fungi showed consistent reduction of disease symptoms for fungal pathogens such as *Phytophthora, Fusarium, Chalara, Pythium, Rhizoctonia, Sclerotium, Verticillium, Aphanomyces.* Several hypotheses have been put forwarded to explain the mechanisms of plant disease

Some of them include creating a mechanical barrier for the pathogen penetration, thickening of cell wall through lignification and polysaccharide production that stops the entry of root pathogen, stimulation of the host roots to produce and accumulate sufficient concentration of metabolites like terpenes and phenols, imparting resistance to the host tissue against pathogen invasion, stimulating flavonolic wall infusions to prevent lesion formation by the pathogen, producing antifungal and antibacterial antibiotics, competing with the pathogens for the uptake of essential nutrients in the rhizosphere and at the roots surface, competitions in the roots and thus preventing the pathogen to get access to the roots. Harboring more actinomycetes antagonistic to root

effects such as changes in their morpho-physiological traits [65–72].

like reduced tillage, low phosphorus fertilizer usage, and perennialized cropping systems [59, 60]. In the agroecosystems the quality of the soil and the productivity of the land can be enhanced by colonization of AM fungi. It enhances the constant masses, soil aggregate stability, rapidity of soil recovery, and significantly increases extra-radical hyphal mycelium in the soil. This is due to a soil protein known as glomalin, that is thought to be of AM fungal origin. Glomalin is responsible for improving soil aggregate water stability and for

*4.1.8 Quality of soil*

decreasing soil erosion [61].

*4.1.9 Water stress tolerance*

development [62–64].

*4.1.11 Disease control*

*4.1.10 Plant tolerance to stressful circumstances*

control by mycorrhizal fungi [75–77].

**24**

pathogen [78–81].

Modern sustainable agriculture demands for a low-input and more naturebased system having role of soil loving microorganisms that are able to accelerate plant nutrition, health and soil, quality, also under stressful environments. All of these demands are being fulfilled by AM fungi. Its use in increasing food production is far and wide; therefore, is a better tool for modern sustainable agriculture particularly as biocontrol agent. Encouragement of AM as a tool for sustainable agriculture usage is of immense importance. Exploitation of AM for promoting a bio-healthy agriculture can significantly reduce the use of synthetic fertilizers and other chemicals resulting in agricultural improvement. Hence, using AM fungi as a biocontrol agent in modern sustainable agriculture, in terms of various parameters like reduction of damage caused by various pathogens, cost effectiveness, energy saving and also as an environment friendly, is a promising perspective for a sustainable agricultural system. The primary focus of future research should be on the identification of genes and gene products controlling the AMF mediated growth and development regulation under stressful cues. Identification of both host as well as AMF specific protein factors regulating symbiotic association and the major cellular and metabolic pathways under different environmental stresses can be hot areas for future research in this field.
