Halotolerant Microbiome and Their Role in Ameliorating Salt Stress

Soil salinity is one of the most significant problems in the twenty-first century that adversely affects the worldwide agricultural production. It not only affects aboveground biome but also belowground biome. Excessive amount of salt in soil disrupts the existence and development of plants as well as community composition of microbes. High salt concentration in water makes it unavilable for plants because of high osmotic potential which can lead to the death or dormancy of microorganisms in hypertonic environments. Some microbes called halotolerant microbes can support plant growth under salt stress conditions. Beneficial microorganisms have the ability to stimulate plant antioxidant systems and control the activity of enzymes like superoxide dismutase, catalase and peroxidase, facilitating in the ability of plants to neutralise reactive oxygen species and defend against the deleterious effects of salt. It is also known that salt-tolerant microorganisms containing ACC deaminase minimise salt stress in plants by lowering ethylene levels. Some mechanisms like compatible solute accumulation, balance of potassium and sodium in cells, osmoadaptation and osmoregulation and extracellular polymeric substance production help microbes to survive in salt-affected environments and to maintain rhizospheric zone that promotes the development of the plants.