Harnessing plant growth promoting rhizobacteria to bolster drought tolerance in plants
K. Kesavardhini, Isra’a M. Essa, Ashish Kumar Nayak, Hasanain A. J. Gharban, K. Veena Gayathri, P. Saranraj
Abstract
Plant Growth Promoting Rhizobacteria (PGPR), significantly enhance plant resilience to abiotic stresses, especially drought. Drought stress negatively affects plant physiological and biochemical processes, hence restricting growth and productivity. PGPR mitigate these effects through many direct and indirect mechanisms, including the modulation of phytohormones, increase of nutrient solubility, and the production of exopolysaccharides, siderophores and ACC deaminase. These favorable microbes promote root architecture, facilitate better water uptake, and activate antioxidant defense mechanisms, thereby lowering oxidative damage from reactive oxygen species. PGPR cause systemic tolerance through triggering signal cascades to affect gene expression under drought stress. Their ability to establish symbiosis with the host plants enables enhanced tolerance to stresses and sustainable growth in water-limited conditions. Recent advances in molecular biology and omics technologies have identified the functional genes and metabolic pathways responsible for PGPR-mediated drought tolerance, opening up new avenues for the development of bio-formulations and precision agriculture. In addition, the integration of PGPR into agricultural management is in line with the goals of sustainable agriculture through the reduction of chemical reliance and soil health. While promising at the laboratory scale, field-scale application requires optimization to overcome environmental and microbial survival challenges. Future research should focus on strain selection, formulation stability, and PGPR-plant genotype-soil microbiome interaction. The use of PGPR in drought management is a powerful, ecologically friendly strategy for productivity enhancement in areas that are arid or semi-arid. Beneficial soil bacteria enhance plant drought resilience through natural mechanisms. Reduces need for chemical fertilizers by improving nutrient and water uptake. Supports sustainable farming in water-scarce regions via eco-friendly solutions. Boosts crop yields and soil health under climate change stress. Offers a promising alternative to traditional agricultural inputs.