SAPK10-Mediated Phosphorylation on WRKY72 Releases Its Suppression on Jasmonic Acid Biosynthesis and Bacterial Blight Resistance

Abstract

Bacterial blight caused by the infection of Xanthomonas oryzae pv. oryzae (Xoo) is a devastating disease that severely challenges the yield of rice. Here, we report the identification of a "SAPK10-WRKY72-AOS1" module, through which Xoo infection stimulates the suppression of jasmonic acid (JA) biosynthesis to cause Xoo susceptibility. WRKY72 directly binds to the W-box in the promoter of JA biosynthesis gene AOS1 and represses its transcription by inducing DNA hypermethylation on the target site, which finally led to lower endogenous JA level and higher Xoo susceptibility. Abscisic acid (ABA)-inducible SnRK2-type kinase SAPK10 phosphorylates WRKY72 at Thr 129. The SAPK10-mediated phosphorylation impairs the DNA-binding ability of WRKY72 and releases its suppression on AOS1 and JA biosynthesis. Our work highlights a module of how pathogen stimuli lead to plant susceptibility, as well as a potential pathway for ABA-JA interplay with post-translational modification and epigenetic regulation mechanism involved.