title: Loss-of-function of Arabidopsis receptor-like kinase BIR1 activates cell death and defense responses mediated by BAK1 and SOBIR1.
abstract: The Arabidopsis receptor-like kinase (RLK) BIR1 (BAK1-INTERACTING RECEPTOR-LIKE KINASE 1) functions as a negative regulator of plant immunity. Previous work showed that loss-of-function of BIR1 leads to constitutive activation of cell death and defense responses. These autoimmune phenotypes are partially dependent on another RLK, SOBIR1. In order to identify additional components involved in the BIR1-regulated plant defense signaling pathway, a suppressor screen was carried out in the bir1-1 pad4-1 mutant background. Mutations in the suppressor mutants were identified by genetic mapping and re-sequencing of the mutant genomes. A number of suppressor mutants were found to carry mutations in an additional RLK, BAK1, indicating that BAK1 is required for activation of cell death and defense responses in bir1-1. Co-immunoprecipitation analysis revealed that BAK1 and SOBIR1 associate with each other in planta when the function of BIR1 is compromised. Although BAK1 was previously characterized as a negative regulator of cell death, our study highlights a novel role of BAK1 in promoting cell death and defense responses in conjunction with SOBIR1.
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Institute of Biological Sciences, Zhongguancun Life Science Park, 7 Science Park Road, Beijing, 102206, China.
authors.forename: Xingchuan
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Biochemistry & Biophysics, Institute for Plant Genomics & Biotechnology, Texas A&M University, College Station, TX, 77843, USA.
authors.forename: Ping
authors.initials: P
authors.lastname: He
authors.affiliation: Department of Botany, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4. yuelin.zhang@ubc.ca.
authors.forename: Yuelin
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D017360:Arabidopsis / Q000166:cytology* / Q000201:enzymology / Q000276:immunology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D016923:Cell Death; D004789:Enzyme Activation / Q000187:drug effects; D005408:Flagellin / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D057865:Plant Immunity / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D017382:Reactive Oxygen Species; D005408:Flagellin; D011494:Protein Kinases; C000593371:SOBIR protein, Arabidopsis; C463660:BAK1 protein, Arabidopsis; C570514:BIR1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases
keywords: BAK1-INTERACTING RECEPTOR-LIKE KINASE 1 (BIR1); BRASSINOSTEROID INSENSITIVE 1-ASSOCIATED RECEPTOR KINASE 1 (BAK1); SUPPRESSOR OF BIR1-1 1 (SOBIR1); cell death; plant immunity; receptor-like kinase