Mycosphere Essay 17 Arbuscular mycorrhizal symbiosis and drought tolerance in crop plants

Drought dramatically reduces crop yield, therefore remains as a major threat to food security. Overcoming drought by crop plants is a complex phenomenon - where plants find ways mainly through physiological adaptation. However, in nature, the plants rely also on microbes for mitigating the drought effects. Below ground association of plant roots with rhizosphere microorganisms for tolerating drought has been though established earlier, the exact mechanism is being understood only recently. The role of below ground microbes, particularly by the arbuscular mycorrhizal fungi (AMF), in drought tolerance by crop plants is currently a key research topic. The significance and highlights of the recent research as well as the past understanding of mechanisms by which crop plants tolerate drought through association of soil beneficial microbes, particularly with that of the AMF, is discussed in this review.