Contribution of AMF in the Remediation of Drought Stress in Soybean Plants

Abstract

Amongst various oil-seed crops grown across the world, soybean (Glycine max L. Merrill) is globally important as a high source of protein and oil for human consumption and is also being used as potential feed for animals. Soybean is grown under rain-fed conditions in the tropics and subtropics in the marginal lands with less amount of external application of chemical fertilizers. The frequent climate variations have created a number of biotic and abiotic stresses, drought being a major abiotic stress which adversely affects the soybean productivity. Thus, to enhance the productivity of soybean, besides managing the nutrients, stress management is of utmost importance. There is a great opportunity of application of microbes especially arbuscular mycorrhizal fungi (AMF) where its application alone or in combination with plant growth promoting rhizobacteria (PGPR) can help in nutrient mobilization and remediation of plant stresses. AMF are a ubiquitous group of soil fungi known to colonize roots of plants belonging to more than ninety per cent of plant families. In this chapter, detailed account of work done on the mycorrhizal symbiosis and its role in alleviation of drought stress has been presented. We have also described mechanisms underlying drought tolerance in AM-colonized soybean plants. The information on understanding interactions between AMF and PGPR and agronomic practices is also provided which would help in the abiotic stress tolerance of soybean plants. In addition, a brief account on the production methods of AMF and availability of AMF inocula is also provided.