OsVQ32–OsWRKY53 Module Regulates Rice Resistance to Bacterial Blight by Suppressing OsPrx30-Mediated ROS Scavenging

WRKY transcription factors play crucial roles in regulating plant immune responses. Our previous research showed that OsWRKY53 negatively affects rice resistance to bacterial blight by reducing the thickness of the cell wall. In this study, we identified a physical interaction between the OsWRKY53 and the OsVQ32, revealing that the OsWRKY53 functions as a downstream component of the OsMPK4-OsVQ32 cascade. OsWRKY53 can directly bind to the promoter of OsPrx30, a gene that negatively affects rice resistance to bacterial blight, thereby activating its expression. OsWRKY53-overexpressing plants exhibited a significant increase in peroxidase activity and a decrease in hydrogen peroxide content, whereas the opposite effects were observed in the oswrky53 mutants. Furthermore, we found that the interaction between OsVQ32 and OsWRKY53 forms a complex that represses OsPrx30 transcription by enhancing the DNA-binding activity of OsWRKY53. OsVQ32 phosphorylation by the OsMPK4 further enhanced this suppression. In conclusion, our findings suggest that the OsVQ32-OsWRKY53 complex regulates the expression of OsPrx30, modulating resistance to bacterial blight by suppressing the scavenging of reactive oxygen species.