Arabidopsis Receptor-like kinase BIR1 negatively regulates cell death mediated by BAK1
Y. LIU (1), Y. Zhang (1) (1) University of British Columbia, Canada

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. 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 when the function of BIR1 is compromised. Our study revealed a novel role of BAK1 in promoting cell death in conjunction with SOBIR1 and BIR1 inhibits cell death mediated by BAK1 and SOBIR1

Abstract Number: P17-563
Session Type: Poster