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

Abstract

Summary 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.

Weighted Gene Co-Expression Network Coupled with a Critical-Time-Point Analysis during Pathogenesis for Predicting the Molecular Mechanism Underlying Blast Resistance in Rice

“…Thus, they may play important roles in the regulation of defenseresponsive genes. The WRKY104 was a positive regulator enhancing the resistance to M. oryzae by up-regulating pathogenesis-related (PR) genes as also shown in recent reports (Hou et al 2019). Additionally, the higher expression of R genes LOC_Os11g11990, LOC_Os11g43700, and LOC_Os12g17430 in the Piz-t-KJ201 interaction system were also observed, which have also been implicated in stress responses (Zheng et al 2014).…”

Abscisic acid promotes jasmonic acid biosynthesis via a ‘SAPK10‐bZIP72‐AOC’ pathway to synergistically inhibit seed germination in rice (Oryza sativa)

“…For example, MPK3/MPK6 phosphorylates WRKY53 to enhance its transcriptional activity on defense‐related genes (Chujo et al ., 2014). By contrast, WRKY72 had weakened trans‐activation on JA synthesis genes when phosphorylation occurred on its 129 th threonine (Hou et al ., 2019). In this study, we revealed the comprehensive effects of SAPK10‐mediated phosphorylation on the target proteins.…”

“…In vitro kinase assays were performed as previously described (Hou et al, 2019). Briefly, for the SAPK10 autophosphorylation assay, GST, GST-SAPK10 or different mutated versions of GST-SAPK10 (GST-SAPK10 S177A , GST-SAPK10 T178A and GST-SAPK10 S177A/T178A ) was expressed in Transetta (DE3) chemically competent cell (Transgen), and purified using the GST-Sefinose TM Kit (Sangon Biotech, Shanghai, China) according to the manufacturer's instructions, respectively.…”

Osmotic stress activated protein kinase 5 (SAPK5) positively regulates immune response and blast resistance in rice

“…In Arabidopsis, SnRK2.6/OST1 and SnRK2.8 confer to bacterial pathogen resistance (Melotto et al 2006;Lee et al 2015). Studies also have suggested that the rice SnRKs, including SAPK3, 5, 7, 9 and 10, are likely involved in resistance regulation against bacterial pathogen (Xu et al 2013;Hou et al 2019;Zhang et al 2019). However, it is unknown whether SnRKs regulate resistance against fungal pathogens.…”

“…SAPK9 is able to form a protein complex with the molecular chaperones, OsSGT1 and OsHsp90, to regulate rice resistance to bacterial blight (Zhang et al 2019). SAPK10 is also involved in bacterial pathogen resistance through phosphorylation WRKY72 to releases its suppression on jasmonic acid (JA) biosynthesis (Hou et al 2019). However, the role of rice SnRK2s members in fungal pathogen resistance remains largely unknown.…”