Concurrent Session
Chunpeng An
Postdoctoral researcher
Max Planck Institute for Plant Breeding Research
Köln, Nordrhein-Westfalen, Germany
Shoucai Ma
Xianghu Laboratory
Hangzhou, China, Zhejiang, China (People's Republic)
Aaron Lawson
Postdoctoral researcher
Max Planck Institute for Plant Breeding Research
Koln, Nordrhein-Westfalen, Germany
Yu Cao
School of Life Sciences, Westlake University, Institute of Biology, Westlake Institute for Advanced Study, Westlake Laboratory of Life Sciences and Biomedicine
Hangzhou, Zhejiang, China (People's Republic)
Yue Sun
School of Life Sciences, Westlake University, Institute of Biology, Westlake Institute for Advanced Study, Westlake Laboratory of Life Sciences and Biomedicine
Hangzhou, Zhejiang, China (People's Republic)
Eddie Yong Jun Tan
Nanyang Technological University Singapore
Singapore, Singapore
Jinheng Pan
School of Life Sciences, Westlake University, Institute of Biology, Westlake Institute for Advanced Study, Westlake Laboratory of Life Sciences and Biomedicine
Hangzhou, Zhejiang, China (People's Republic)
Jan Jirschitzka
Institute of Biochemistry, University of Cologne, Cologne, Germany.
C, Nordrhein-Westfalen, Germany
Paul Schulze-Lefert
Professor
Max Planck Institute for Plant Breeding Research
Köln, Nordrhein-Westfalen, Germany
Jijie Chai
Professor
Westlake University
Hangzhou, Zhejiang, China (People's Republic)
Nucleotide-binding leucine-rich repeat (NLR) proteins play a pivotal role in plant immunity by recognizing pathogen effectors. Potato immune receptor Rx mediates immunity to Potato Virus X (PVX) by two distinct immune responses: extreme resistance (ER) without host cell death and a hypersensitivity response (HR) associated with cell death. Helper NLRs, termed NRC proteins, are required for Rx-mediated ER and HR. We aim to investigate the mechanisms of Rx-NRC-mediated immunity both with and without host cell death. Unlike most NLRs, NRC2 belongs to a small NLR group with constitutively high expression levels without self-activation of the receptor. We found that Solanum lycopersicum (tomato) NRC2 (SlNRC2) forms dimers, tetramers, and higher-order oligomers (filaments), which stabilize the inactive state and sequester it from assembling into an active form. Unexpectedly, the cryo-electron microscopy structures reveal inositol hexakisphosphate (IP6) or pentakisphosphate (IP5) bound to the LRR domain of SlNRC2, which is essential for Rx-mediated immunity. Our study points a novel negative regulatory mechanism of NLR activation and suggests inositol phosphates as cofactors of NRCs. We explore the mechanism of how Rx activates NRCs and the determinants underlying ER and HR-associated immunity.