title: A truncated NLR protein, TIR-NBS2, is required for activated defense responses in the exo70B1 mutant.
abstract: During exocytosis, the evolutionarily conserved exocyst complex tethers Golgi-derived vesicles to the target plasma membrane, a critical function for secretory pathways. Here we show that exo70B1 loss-of-function mutants express activated defense responses upon infection and express enhanced resistance to fungal, oomycete and bacterial pathogens. In a screen for mutants that suppress exo70B1 resistance, we identified nine alleles of TIR-NBS2 (TN2), suggesting that loss-of-function of EXO70B1 leads to activation of this nucleotide binding domain and leucine-rich repeat-containing (NLR)-like disease resistance protein. This NLR-like protein is atypical because it lacks the LRR domain common in typical NLR receptors. In addition, we show that TN2 interacts with EXO70B1 in yeast and in planta. Our study thus provides a link between the exocyst complex and the function of a 'TIR-NBS only' immune receptor like protein. Our data are consistent with a speculative model wherein pathogen effectors could evolve to target EXO70B1 to manipulate plant secretion machinery. TN2 could monitor EXO70B1 integrity as part of an immune receptor complex.
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Rui
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Howard Hughes Medical Institute and Department of Biology, University of North Carolina at Chapel Hill, North Carolina, United States of America.
authors.forename: Marc T
authors.initials: MT
authors.lastname: Nishimura
authors.affiliation: Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, California, United States of America.
authors.forename: John P
authors.initials: JP
authors.lastname: Vogel
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Na
authors.initials: N
authors.lastname: Liu
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Simu
authors.initials: S
authors.lastname: Liu
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; Graduate School of Chinese Academy of Sciences, Beijing, China.
authors.forename: Yaofei
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Howard Hughes Medical Institute and Department of Biology, University of North Carolina at Chapel Hill, North Carolina, United States of America.
authors.forename: Jeffery L
authors.initials: JL
authors.lastname: Dangl
authors.affiliation: The State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Dingzhong
authors.initials: D
authors.lastname: Tang
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000096:biosynthesis / Q000235:genetics*; D016923:Cell Death / Q000235:genetics; D060467:Disease Resistance / Q000235:genetics* / Q000276:immunology; D005089:Exocytosis / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D015398:Signal Transduction; D033921:Vesicular Transport Proteins / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; C000589008:EXO70B1 protein, Arabidopsis; D008565:Membrane Proteins; D033921:Vesicular Transport Proteins