Phosphate-solubilizing bacteria: roles in phosphorus cycling and ecological agriculture and application as potential biofertilizers

Abstract:

Agricultural soils generally have limited available phosphorus. Although the application of phosphorus fertilizers can alleviate phosphorus deficiency in crops, it brings environmental risks, thereby affecting agroecological stability. Microorganisms are integral components of soil phosphorus cycling and play a crucial role in mediating the availability of phosphorus to plants. Phosphate-solubilizing bacteria (PSB) can solubilize insoluble inorganic and organic phosphorus in the soil, facilitating phosphorus uptake by plant roots and enhancing crop resistance to biotic and abiotic stresses. Currently, the use of PSB as potential biofertilizers has attracted considerable attention and demonstrated broad prospects for sustainable agriculture. This article systematically elucidates the agroecological functions of PSB and expounds the physiological and molecular mechanisms of PSB-mediated phosphorus solubilization and plant growth-promoting effect with consideration to other factors such as organic acids, hydrolases, siderophores, and ACC deaminases. Moreover, we analyzed the impact of PSB on soil microbial communities and their interaction with root exudates, highlighted the key points and challenges in the application and promotion of PSB biofertilizers, and put forward the application of PSB biofertilizers as an effective measure to increase phosphorus fertilizer use efficiency and crop yield. Finally, we proposed suggestions for future research and application of PSB biofertilizers, aiming to promote the application of PSB biofertilizers in ecological agriculture. The efforts aim to mitigate the dual challenges posed by agricultural resources and the environment, meet future needs of global food security, and align with the development trend of green ecological agriculture.