Delineating the role of rhizospheric microbes in the amelioration of hexavalent chromium stress in plants

Hexavalent Chromium is mostly formed from various mining and industrial activities and has severe toxic implications for biotic components. It also hampers soil nutrient profile, thus hindering plant productivity. Bioaccumulation of Cr (VI) in plant tissues reduces plant growth and vigor and poses the risk of transferring the toxic metal to humans through the food chain. It is highly essential to reduce Cr (VI) concentrations in the soil and reduce its transfer into plant tissues. Plant growth-promoting rhizobacterial species are an efficient tool to cater to the problem. The current article discusses the role of such beneficial microbes in the sustainable remediation of Cr (VI) contaminated soil while alleviating stress and promoting growth. Various studies have claimed the expert role of these microbes in Cr (VI) remediation. However, little progress has been made concerning their feasible application in Cr (VI) contaminated soils. One of the major gaps is the lack of understanding of the remediation potential of these PGPRs at a molecular level. Recent strategies, like the synergistic application of PGPRs and microbial immobilization, have been highlighted as feasible methods for the successful remediation of Cr (VI) contaminated soils. The adoption of multi-omics techniques has been proposed for better identification of PGPRs.