Dynamics of arbuscular mycorrhizal symbiosis and its role in nutrient acquisition: An overview

Abstract

Arbuscular mycorrhiza constitute a heterogeneous group of diverse fungal taxa that have been reported to form mutualistic interaction with the roots of more than 90% of all plant species. Accomplishment of this symbiotic interaction requires a high degree of synchronization between the two partners and is based on a finely regulated molecular dialogue. Where plant roots exude strigolactones that stimulate fungal metabolism and branching, fungus releases signaling molecules-myc factors that trigger symbiotic responses in the host plant. Among the various benefits bestowed by this symbiotic association, transport of limiting soil nutrients including phosphorus (P), nitrogen (N), sulphur (S) in exchange for fixed carbon is considered as the key feature which occurs in arbuscule containing host cortical cells. In the last few years, novel transporters involved in this mutualistic interaction have been unravelled. This chapter briefly summarizes the signaling pathways and nutrient exchange involved in the establishment of an effective symbiosis between the host plant and fungus that could provide better insight into the role of mycorrhizal fungi in sustainable agriculture.