The Role of Arbuscular Mycorrhiza Fungi in Drought Tolerance in Legume Crops: A Review

Abstract

Legumes are low-cost but high-yielding crops, which are rich in dietary proteins, vitamins and minerals. Known as mycorrhizal plants, legumes are widely used as model organisms to explore the plant-microbe interactions, especially the symbiotic relationship between plants and rhizosphere microorganisms. Arbuscular mycorrhizal fungi (AMF), an important class of plant-associated microbes, can regulate many physiological and molecular responses of plants. To date, AMF has been commonly used as a bio-fertilizer, whose inoculation to host plants can confer tolerance to different abiotic stresses such as drought, salinity, heat and heavy metals. This review provides an overview of the responses of legumes to drought stress (DS), a summary of the mechanism of AMF-legume symbiosis and its effect on host plant drought tolerance, which taken together reveals the significance of this symbiosis in agriculture. The presented rich information will help understand how host plants benefit from AMF to increase drought tolerance while finetuning their metabolic pathways. The potential and importance of AMF as one of the most effective and environmental-friendly management approaches for enhancing legume crop productivity against DS is highlighted.