Alleviation of Salinity Stress by Microbes

Agricultural production is majorly hampered by the negative impact of both biotic and abiotic stress in most developing countries. Among abiotic stresses, soil salinity is a major problem, affecting crop production and responsible for limiting the growth and productivity of plants in different areas of the world due to increasing use of poor quality of water, flooding, over-irrigation, seepage, silting, and a rising water table. In agriculture, salt-tolerant rhizospheric/endophytic microorganisms play an important role in helping alleviate abiotic stresses in plants. Under plant-microbe interactions, plant root-associated microbes, including endophytes, closely interact and cooperate with plants, and mediate important physiological and metabolic processes, thereby enhancing the plant’s tolerance to salinity stress. Several mechanisms have been developed for microbial alleviation of salinity stress in plants, including the production of phytohormones, improving plant nutrient status, production of ACC deaminase, salt exclusion, and enhancing resistance to drought in plant cells. A wide range of micro-organisms are available that have diverse mechanisms for salt stress alleviation in plants. Future research needs to be directed towards field evaluation for the validation of the potential microbes.