Role of Halotolerant Microbes in Plant Growth Promotion Under Salt Stress Conditions

Abstract

The salt-tolerant microorganisms also referred to as halotolerant including bacteria and fungi have the ability to promote growth of plant in salty environment. Presence of certain particular traits like exopolysaccharide production ability, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, production of osmolytes, enhancing nutrient acquisition and activity of antioxidant enzymes as well as maintaining of K+:Na+ ratio make them suitable candidates for promoting plant growth under saline environment. Moreover, the capability of these microbes to fix nitrogen, produce siderophores, solubilize insoluble nutrients, and provision protection against harmful pathogens further accelerates the importance of beneficial microbes in agriculture system. To make use of these environment friendly species as biofertilizers in agricultural system is increasing nowaday to facilitate the plant growth under adverse conditions. The halotolerant bacteria and fungi could be a cost-effective approach to overcome the problem of salinity stress. These halotolerant microbes can be used as biopesticides and biofertilizers and could decrease our reliance on synthetic agrochemicals. These halotolerant microbes are also the most suitable candidates for bioremediation of contaminated environment. This review chapter highlights the significant role of halotolerant microbes for improving crop growth under saline conditions and bioremediation of contaminated environment. The mechanisms used by halotolerant microbes to tolerate salinity as well as promote plant growth under salinity stress have been discussed with selected examples. Also the role of these microbes in environmental sciences has been reviewed. The areas that need further research and future perspectives of this technology have also been discussed in detail.