Plant Growth-Promoting Rhizobacteria for Abiotic Stress Alleviation in Crops

Abstract

Environmental stresses pose a major constraint to agricultural productivity. Studies have indicated an immense potential of plant growth-promoting rhizobacteria (PGPRs) in the mitigation of different abiotic stresses in crops such as temperature, salinity, drought, heavy metal toxicity, etc. Improved plant growth and yield; and enhanced tolerance to various abiotic stresses due to inoculation with PGPRs have been noted in different plants. PGPRs mitigate environmental stress in plants through an array of mechanisms which include phytohormone production, induced systemic tolerance through modulation of physiological responses, osmotic adjustments through production of osmolytes, ACC deaminase activity, exopolysaccharide production, improvement in soil physicochemical properties, production of volatile organic carbon compounds, and induction of stress-responsive genes. Screening, selection, and use of abiotic stress-tolerant PGPRs as bioinoculants are a promising strategies for enhancing crop productivity under stressed environments.