title: Arabidopsis Lectin Receptor Kinases LecRK-IX.1 and LecRK-IX.2 Are Functional Analogs in Regulating Phytophthora Resistance and Plant Cell Death.
abstract: L-type lectin receptor kinases (LecRK) are potential immune receptors. Here, we characterized two closely-related Arabidopsis LecRK, LecRK-IX.1 and LecRK-IX.2, of which T-DNA insertion mutants showed compromised resistance to Phytophthora brassicae and Phytophthora capsici, with double mutants showing additive susceptibility. Overexpression of LecRK-IX.1 or LecRK-IX.2 in Arabidopsis and transient expression in Nicotiana benthamiana increased Phytophthora resistance but also induced cell death. Phytophthora resistance required both the lectin domain and kinase activity, but for cell death, the lectin domain was not needed. Silencing of the two closely related mitogen-activated protein kinase genes NbSIPK and NbNTF4 in N. benthamiana completely abolished LecRK-IX.1-induced cell death but not Phytophthora resistance. Liquid chromatography-mass spectrometry analysis of protein complexes coimmunoprecipitated in planta with LecRK-IX.1 or LecRK-IX.2 as bait, resulted in the identification of the N. benthamiana ABC transporter NbPDR1 as a potential interactor of both LecRK. The closest homolog of NbPDR1 in Arabidopsis is ABCG40, and coimmunoprecipitation experiments showed that ABCG40 associates with LecRK-IX.1 and LecRK-IX.2 in planta. Similar to the LecRK mutants, ABCG40 mutants showed compromised Phytophthora resistance. This study shows that LecRK-IX.1 and LecRK-IX.2 are Phytophthora resistance components that function independent of each other and independent of the cell-death phenotype. They both interact with the same ABC transporter, suggesting that they exploit similar signal transduction pathways.
authors.affiliation: 1 Laboratory of Phytopathology, Plant Sciences Group, Wageningen University, Wageningen, The Netherlands;
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: 2 Plant Research International, Wageningen University;
authors.forename: Jan H G
authors.initials: JH
authors.lastname: Cordewener
authors.affiliation: 2 Plant Research International, Wageningen University;
authors.forename: Antoine H P
authors.initials: AH
authors.lastname: America
authors.affiliation: 3 State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, P. R. China;
authors.forename: Weixing
authors.initials: W
authors.lastname: Shan
authors.affiliation: 1 Laboratory of Phytopathology, Plant Sciences Group, Wageningen University, Wageningen, The Netherlands;|4 Plant-Microbe Interactions, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
authors.forename: Klaas
authors.initials: K
authors.lastname: Bouwmeester
authors.affiliation: 1 Laboratory of Phytopathology, Plant Sciences Group, Wageningen University, Wageningen, The Netherlands;
authors.forename: Francine
authors.initials: F
authors.lastname: Govers
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D016923:Cell Death / Q000502:physiology*; D010838:Phytophthora / Q000502:physiology*; D010935:Plant Diseases / Q000382:microbiology*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C000612801:LecRK-IX.1 protein, Arabidopsis; D011494:Protein Kinases; C099543:ATHLECRK protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases