OsWRKY26 negatively regulates bacterial blight resistance by suppressing expression.

Plants are susceptible to infection by various pathogens with high epidemic potential. pv () causes bacterial blight in rice, one of the most significant diseases in both temperate and tropical regions. In this study, we report the identification and characterization of , a sucrose-inducible transcription factor, that plays a role in the plant defense responses following infection. We found that mutant plants with defective showed enhanced defense response specifically to , indicating that this transcription factor acts as a negative defense regulator. In contrast, mutant plants did not exhibit higher resistance compared to wild-type (WT) plants when infected with the rice blast fungal pathogen . Transcriptomic analysis of mutant and WT plants revealed that several pathogen resistance genes were upregulated in mutants. Of these, we selected for further analysis. Transient expression experiments in rice protoplasts showed that OsWRKY26 repressed the expression of a reporter gene driven by the promoter. Chromatin immunoprecipitation analysis revealed that OsWRKY26 binds directly to the promoter region of . These findings suggest that OsWRKY26 negatively regulates the defense response during infection by repressing as well as other pathogen-related genes such as , , , , , , and