Multifaceted Role of Arbuscular Mycorrhizal Fungi in Crop Growth Promotion: An Overview

The most familiar and common mutualistic association existing in the majority of crop plants is the arbuscular mycorrhizal (AM) symbiosis that aids in crop growth and development. In the plant-AM fungal interaction, the fungi acquire carbon from their host plant and in exchange, the fungi increase the supply of important nutrients in particular phosphorous via expanding the roots into the nutrient absorbing sites. Also, the AM fungi enhance crops performance and existence under different abiotic and biotic stresses through different mechanisms. As a natural crop-root colonizer, AM fungi impart essential micro-and macronutrients thereby promoting crop growth and productivity in nutrient-stressed soils. The AM-fungal mediated crop growth promotion involves several pathways and a sequence of multifarious communications between the crop and the fungus. Owing to its crop growth-promoting activity, several AM fungal species are developed into potential bioinoculants for the ecofriendly management of anthropogenic ecosystems like agriculture. In this chapter, we comprehend the existing knowledge on the role of AM fungi in the establishment and survival of crops under normal and stressful environments that hampers crop growth and development like drought, salinity, heavy metals and infestation by pathogens. In addition, the role of AM fungi in crop growth promotion through nutrient uptake and other pathways, application of AM fungi in improving the water relations and nutritional quality in crop species under unfavourable conditions are also discussed. The exploitation of AM fungal symbiosis in agricultural habitats can lead to the creation of self-sustaining ecosystems for future.