Structure-Function Analysis of Barley NLR Immune Receptor MLA10 Reveals Its Cell Compartment Specific Activity in Cell Death and Disease Resistance

PLoS Pathogens

Yule Liu¹  Ling Zhang²  Qiuyun Wang²  Jie Liu²  Paul Schulze-Lefert³  Qian-Hua Shen³  Cheng Chang⁴  Wenkai Xiao⁴  Frank L. W. Takken⁴  Jijie Chai⁴  Takaki Maekawa⁴  Shiwei Bai⁴ 

[1] Department of Plant Microbe Interactions, Max-Planck Institut Pflanzenzüchtungsforschung, Cologne, Germany;Graduate University of Chinese Academy of Sciences, Beijing, China;School of Life Sciences, Tsinghua University, Beijing, China;State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China

关键词: Cell death;    Cell fusion;    Barley;    Cell signaling;    Leaves;    Cytoplasm;    Cell staining;    Yellow fluorescent protein;   

DOI  :  10.1371/journal.ppat.1002752

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Plant intracellular immune receptors comprise a large number of multi-domain proteins resembling animal NOD-like receptors (NLRs). Plant NLRs typically recognize isolate-specific pathogen-derived effectors, encoded by avirulence (AVR) genes, and trigger defense responses often associated with localized host cell death. The barley MLA gene is polymorphic in nature and encodes NLRs of the coiled-coil (CC)-NB-LRR type that each detects a cognate isolate-specific effector of the barley powdery mildew fungus. We report the systematic analyses of MLA10 activity in disease resistance and cell death signaling in barley and Nicotiana benthamiana. MLA10 CC domain-triggered cell death is regulated by highly conserved motifs in the CC and the NB-ARC domains and by the C-terminal LRR of the receptor. Enforced MLA10 subcellular localization, by tagging with a nuclear localization sequence (NLS) or a nuclear export sequence (NES), shows that MLA10 activity in cell death signaling is suppressed in the nucleus but enhanced in the cytoplasm. By contrast, nuclear localized MLA10 is sufficient to mediate disease resistance against powdery mildew fungus. MLA10 retention in the cytoplasm was achieved through attachment of a glucocorticoid receptor hormone-binding domain (GR), by which we reinforced the role of cytoplasmic MLA10 in cell death signaling. Together with our data showing an essential and sufficient nuclear MLA10 activity in disease resistance, this suggests a bifurcation of MLA10-triggered cell death and disease resistance signaling in a compartment-dependent manner.

【 授权许可】

CC BY