Drought-tolerant plant growth-promoting rhizobacteria alleviate drought stress and enhance soil health for sustainable agriculture: A comprehensive review

Climate change has exacerbated the impact of abiotic stresses, mainly drought, on plant production. Plant selection, breeding, and genetic engineering to increase drought tolerance are costly and time-consuming. To mitigate drought stress, plants employ adaptive mechanisms and interact with beneficial microorganisms, such as plant growth-promoting rhizobacteria (PGPR). Inoculating plant roots with various PGPR species promotes drought tolerance through a network of cellular, physiological, and biochemical mechanisms, including enhanced root elongation, increased phytohormone production, and synthesis of volatile organic compounds. PGPR colonization represents an environmentally sustainable agricultural technique that enhances plant growth, development, and yield by facilitating improved tolerance to environmental challenges. The current review provides an overview of the impact of drought stress on plant growth and development, detailing how PGPR induce physiological, morphological, and molecular responses to mitigate drought stress.