Phosphate-solubilizing bacteria: a review of diversity, mechanisms, and applications in sustainable agriculture

Phosphorus (P) is an essential nutrient for plant growth but the global supply is limited, and over-reliance on chemical phosphate fertilizers can lead to soil pollution and ecological imbalance. Phosphate-solubilizing bacteria (PSB) can convert insoluble P in the soil into plant-available forms and enhance the P utilization efficiency of crops. The application of PSB can also improve the soil ecological environment and contribute to the sustainable development of agriculture. This review systematically summarizes the diversity and distribution of PSB. It comprehensively investigates the mechanisms through which PSB enhance soil P utilization efficiency, focusing on the following aspects: the acid-mediated solubilization of inorganic P, the enzymatic hydrolysis of organic P, the interactions between PSB and plant roots, and the interactions between PSB and rhizosphere microorganisms. Furthermore, recent advances in the development and application of PSB-based biofertilizers are also reviewed. Potential future research directions and the anticipated challenges within this field are also discussed, to develop innovative strategies for alleviating P deficiency in agricultural soils.