Plasma membrane H ⁺ ‐ <scp>ATPase OsA1</scp> enhances soil organic phosphorus mineralization via <i>Bacillus cereus</i> recruitment in rice

Organic phosphorus (P), which accounts for c. 50% of total soil P, is not directly available for plant uptake and must be first mineralized. Plasma membrane (PM) H⁺-ATPase facilitates the mobilization of insoluble inorganic P by energizing the release of organic anions from roots. However, its role in modulating the rhizosphere microbiome to facilitate soil organic P mineralization remains unclear. To address the gap, we investigated the role of PM H⁺-ATPase in recruiting microbiota for soil organic P mineralization through high-throughput sequencing and metabolite analysis. Under low P (LP) conditions in nonsterilized soil, wild-type (WT) rice seedlings exhibited 59%, 73%, and 66% greater shoot P concentration than three PM H⁺-ATPase gene OsA1 mutants, that is, osa1-1, osa1-2, and osa1-3, respectively. Such growth advantage reduced to 33%, 47%, and 39% in sterilized soil, suggesting a microbial contribution. Under LP conditions, organic P mineralization efficiency in the WT rhizosphere was four times greater than under normal P (NP) conditions, whereas no significant difference was observed in the osa1-1 mutant. The abundance of Bacillus was significantly higher in the WT rhizosphere than in osa1-1 under LP. Compared with the osa1-1 rice, WT exhibits significantly higher malate concentration, which could stimulate the growth of Bacillus cereus. Inoculation with B. cereus significantly increased P uptake in both WT and OsA1 mutants compared with the uninoculated control under LP. Together, these findings suggest that OsA1 promoted soil organic P mineralization by recruiting Bacillus through malate exudation. This highlights a cooperative interaction between PM H⁺-ATPase and the rhizosphere microbiome, with important implications for enhancing soil organic P mineralization and P-use efficiency in rice production.