Lu Junxing, Liang Wanwan, Zhang Nanbing, van Wersch Solveig, Li Xin
College of Life Science, Chongqing Normal University, Chongqing, China.
Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada.
Front Plant Sci. 2022 Jun 3;13:888449. doi: 10.3389/fpls.2022.888449. eCollection 2022.
Plants employ multi-layered immune system to fight against pathogen infections. Different receptors are able to detect the invasion activities of pathogens, transduce signals to downstream components, and activate defense responses. Among those receptors, nucleotide-binding domain leucine-rich repeat containing proteins (NLRs) are the major intracellular ones. CHILLING SENSITIVE 3 (CHS3) is an Arabidopsis NLR with an additional Lin-11, Isl-1 and Mec-3 (LIM) domain at its C terminus. The gain-of-function mutant, , exhibiting severe dwarfism and constitutively activated defense responses, was selected as a genetic background in this study for a forward genetic screen. A mutant allele of was isolated as a partial suppressor of , suggesting that HSP90 is required for CHS3-mediated defense signaling. In addition, HSP90 is also required for the autoimmunity of the and gain-of-function transgenic lines, suggesting a broad role for HSP90 in NLR-mediated defense. Overall, our work indicates a larger contribution of HSP90 not only at the sensor, but also the helper NLR levels.
植物利用多层免疫系统来对抗病原体感染。不同的受体能够检测病原体的入侵活动，将信号传递给下游组分，并激活防御反应。在这些受体中，富含亮氨酸重复序列的核苷酸结合结构域蛋白（NLRs）是主要的细胞内受体。低温敏感3（CHS3）是拟南芥中的一种NLR，在其C末端有一个额外的Lin-11、Isl-1和Mec-3（LIM）结构域。功能获得性突变体表现出严重的矮化和组成型激活的防御反应，在本研究中被选为正向遗传筛选的遗传背景。一个突变等位基因被分离出来作为的部分抑制子，表明HSP90是CHS3介导的防御信号传导所必需的。此外，HSP90对于和功能获得性转基因系的自身免疫也是必需的，这表明HSP90在NLR介导的防御中具有广泛作用。总体而言，我们的工作表明HSP90不仅在传感器水平，而且在辅助NLR水平上都有更大的作用。
