J Integr Plant Biol

• • 上一篇    

  

E3 ubiquitin ligase-mediated degradation of Rab GTPase suppresses an MAPKK and activates immunity in rice

Su Jiang1,2, Ziwen Gong2, Chenggang Li3,4, Hui Tao2, Feng He2, Xiao Xu2, Min Wang2, Jisong Wang2, Yuancheng Sun1, Qin Feng2, Zeyun Hao2, Xiaoman You2, Ruyi Wang2, Jun Wu1,4, Guo‐Liang Wang5, Yinghui Xiao1,4*, Yuese Ning2* and Dan Wang1,4*   

  1. 1. College of Agronomy, Hunan Agricultural University, Changsha 410128, China

    2. State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of AgriculturalSciences, Beijing 100193, China

    3. State Key Laboratory of Hybrid Rice and Hunan Hybrid Rice Research Center, Changsha 410125, China

    4. Yuelushan Laboratory, Changsha 410128, China

    5. Department of Plant Pathology, The Ohio State University, Columbus OH 43210, USA

    *Correspondences: Yinghui Xiao (xiaoyh@hunau.edu.cn); Yuese Ning (ningyuese@caas.cn); Dan Wang (jessicawangdan@163.com,Dr. Wang is fully responsible for the distribution of all materials associated with this article)

  • Supported by:
    This project was supported by grants from the Innovation Program of the Chinese Academy of Agricultural Sciences (CAAS‐CSCB‐202301) and the National Natural Science Foundation of China (32161143009 and 32272505) to Y.N., the National Natural Science Foundation of China (U24A20388) to R.W, and the National Natural Science Foundation of China (32372141) to H.T.

Abstract: Small G proteins, functioning as monomeric GTPases, are critical molecular switches that regulate diverse processes in plants. However, little is known about their protein homeostasis during immune responses. Here, we demonstrate that OsRab11C1, encoding a Rab-type GTPase, is transcriptionally upregulated upon Magnaporthe oryzae infection. Strikingly, loss of OsRab11C1 enhances rice blast resistance, concomitant with increased defense gene expression, MAPK activation, and ROS burst. Mechanistically, we identify the E3 ubiquitin ligase EL5 as an interactor that ubiquitinates and targets OsRab11C1 for degradation via the 26S proteasome. Consistently, EL5 acts upstream of OsRab11C1 and positively regulates rice immunity. Further analysis reveals that OsRab11C1 interacts with and stabilizes mitogen-activated protein kinase kinase OsMKK6, thereby facilitating its autophosphorylation activity. In return, OsMKK6 acts as a negative regulator of rice programmed cell death and immunity. Collectively, our findings unveil a dynamic EL5-OsRab11C1-OsMKK6 signaling module that orchestrates rice immunity against pathogen invasion.

Key words: MAPK, programmed cell death, Rab‐type GTPase, rice immunity, ubiquitination

[an error occurred while processing this directive]