The Monocot-Specific Receptor-like Kinase SDS2 Controls Cell Death and Immunity in Rice

Publication date: Available online 22 March 2018
Source:Cell Host & Microbe
Author(s): Jiangbo Fan, Pengfei Bai, Yuese Ning, Jiyang Wang, Xuetao Shi, Yehui Xiong, Kai Zhang, Feng He, Chongyang Zhang, Ruyi Wang, Xiangzong Meng, Jinggeng Zhou, Mo Wang, Gautam Shirsekar, Chan Ho Park, Maria Bellizzi, Wende Liu, Jong-Seong Jeon, Ye Xia, Libo Shan, Guo-Liang Wang
Programmed cell death (PCD) plays critical roles in plant immunity but must be regulated to prevent excessive damage. The E3 ubiquitin ligase SPL11 negatively regulates PCD and immunity in plants. We show that SPL11 cell-death suppressor 2 (SDS2), an S-domain receptor-like kinase, positively regulates PCD and immunity in rice by engaging and regulating SPL11 and related kinases controlling defense responses. An sds2 mutant shows reduced immune responses and enhanced susceptibility to the blast fungus Magnaporthe oryzae. Conversely, SDS2 over-expression induces constitutive PCD accompanied by elevated immune responses and enhanced resistance to M. oryzae. SDS2 interacts with and phosphorylates SPL11, which in turn ubiquitinates SDS2, leading to its degradation. In addition, SDS2 interacts with related receptor-like cytoplasmic kinases, OsRLCK118/176, that positively regulate immunity by phosphorylating the NADPH oxidase OsRbohB to stimulate ROS production. Thus, a plasma membrane-resident protein complex consisting of SDS2, SPL11, and OsRLCK118/176 controls PCD and immunity in rice.

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Teaser

Plant cell death and immunity must be strictly controlled. Fan et al. show that the monocot-specific RLK SDS2 phosphorylates the E3 ligase SPL11 to positively regulate cell death and immunity. SDS2 also interacts with the receptor-like cytoplasmic kinases RLCK118 and RLCK176 to regulate immunity via the NADPH oxidase OsRbohB.


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