An Ustilaginoidea virens Nuclear Effector SCRE7 Inhibits Rice Immunity via Suppressing OsLBD11/12‐Promoted Transcription of OsCPS2

ABSTRACT Phytopathogenic fungi secrete a great number of effector proteins into various organelles of host plants and suppress plant immunity through different mechanisms. In this study, we identify SCRE7 as a unique nuclear effector that is essential for U. virens infection. SCRE7 interacts with a transcription factor OsLBD11/12 in rice nuclei. Interestingly, defence responses and rice resistance against bacterial and fungal diseases are negatively modulated by SCRE7, but positively regulated by OsLBD11/12. Consistently, transcriptome analyses revealed that SCRE7 and OsLBD11/12 oppositely regulate multiple immune‐related pathways in rice. Furthermore, we demonstrated that OsLBD11/12 activates the transcription of OsCPS2 encoding a positive immune regulator through specifically binding to the cis ‐element in the OsCPS2 promoter. SCRE7 attenuates the binding of OsLBD11/12 to the cis ‐element and thereby inhibits the transcriptional activity of the transcription factor and rice immunity. The findings not only represent an unidentified infection strategy in U. virens , but also provide candidate gene targets for the creation of disease‐resistant germplasms in rice.