Microbes in Cahoots with Plants: MIST to Hit the Jackpot of Agricultural Productivity during Drought.

Drought conditions marked by water deficit impede plant growth thus causing recurrent decline in agricultural productivity. Presently, research efforts are focussed towards harnessing the potential of microbes to enhance crop production during drought. Microbial communities, such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) buddy up with plants to boost crop productivity during drought via microbial induced systemic tolerance (MIST). The present review summarizes MIST mechanisms during drought comprised of modulation in phytohormonal profiles, sturdy antioxidant defence, osmotic grapnel, bacterial exopolysaccharides (EPS) or AMF glomalin production, volatile organic compounds (VOCs), expression of fungal aquaporins and stress responsive genes, which alters various physiological processes such as hydraulic conductance, transpiration rate, stomatal conductivity and photosynthesis in host plants. Molecular studies have revealed microbial induced differential expression of various genes such as (), (ABA-responsive gene) in , (regulates energy and carbohydrate metabolism), (protein kinase), (stress responsive pathway), , and (chaperones in ABA signalling) in treated rice, , (encoding potassium channels) in Lycium, and (IAA biosynthesis) in AMF inoculated , , , , , and (polyamine biosynthesis) in PGPR inoculated , 14-3-3 genes (- genes in ABA signalling pathways) in AMF treated , , (ethylene biosynthesis), jasmonate gene in chick pea, (SA regulated gene), (JA marker genes) and (ethylene-response gene) in treated plants. Moreover, the key role of miRNAs in MIST has also been recorded in RA treated chick pea plants.