Plant growth-promoting rhizobacteria: Salt stress alleviators to improve crop productivity for sustainable agriculture development

Soil salinity, a growing issue worldwide, is a detrimental consequence of the ever-changing climate, which has highlighted and worsened the conditions associated with damaged soil quality, reduced agricultural production, and decreasing land areas, thus resulting in an unsteady national economy. In this review, halo-tolerant plant growth-promoting rhizo-microbiomes (PGPRs) are evaluated in the salinity-affected agriculture as they serve as excellent agents in controlling various biotic-abiotic stresses and help in the augmentation of crop productivity. Integrated efforts of these effective microbes lighten the load of agro-chemicals on the environment while managing nutrient availability. PGPR-assisted modern agriculture practices have emerged as a green strategy to benefit sustainable farming without compromising the crop yield under salinity as well as salinity-affected supplementary stresses including increased temperature, drought, salinity, and potential invasive plant pathogenicity. PGPRs as bio-inoculants impart induced systemic tolerance (IST) to plants by the production of volatile organic compounds (VOCs), antioxidants, osmolytes, extracellular polymeric substances (EPS), phytohormones, and ACC-deaminase and recuperation of nutritional status and ionic homeostasis. Regulation of PGPR-induced signaling pathways such as MAPK and CDPK assists in salinity stress alleviation. The Next Gen Agriculture consists of the application of designer crop microbiomes through gene editing tools, for instance, CRISPR, and engineering of the metabolic pathways of the microbes so as to gain maximum plant resistance. The utilization of omics technologies over the traditional approaches can fulfill the criteria required to increase crop yields in a sustainable manner for feeding the burgeoning population and augment plant adaptability under climate change conditions, ultimately leading to improved vitality. Furthermore, constraints such as the crop specificity issue of PGPR, lack of acceptance by farmers, and legal regulatory aspects have been acknowledged while also discussing the future trends for product commercialization with the view of the changing climate.

Automated summary

Soil salinity, caused by the changing climate, has become a serious problem worldwide, resulting in damaged soil quality, reduced agricultural production, and decreasing land areas, which has a negative impact on the national economy. Halo-tolerant plant growth-promoting rhizo-microbiomes (PGPRs) are evaluated as excellent agents in controlling biotic-abiotic stresses and promoting crop productivity in salinity-affected agriculture. PGPR-assisted modern agriculture practices have emerged as a green strategy to ensure sustainable farming and mitigate salinity-related stresses. The regulation of PGPR-induced signaling pathways and the application of gene editing tools like CRISPR can contribute to improved plant resistance and adaptability under climate change conditions. The utilization of omics technologies can also enhance crop yields in a sustainable manner, ultimately leading to improved vitality. However, the challenges of crop specificity, acceptance by farmers, and legal regulations need to be addressed for product commercialization in response to climate change.