title: An Arabidopsis (malectin-like) leucine-rich repeat receptor-like kinase contributes to downy mildew disease.
abstract: Biotrophic filamentous plant pathogens frequently establish intimate contact with host cells through intracellular feeding structures called haustoria. To form and maintain these structures, pathogens must avoid or suppress defence responses and reprogramme the host cell. We used Arabidopsis whole-genome microarrays to characterize genetic programmes that are deregulated during infection by the biotrophic' oomycete downy mildew pathogen, Hyaloperonospora arabidopsidis. Marked differences were observed between early and late stages of infection, but a gene encoding a putative leucine-rich repeat receptor-like kinase (LRR-RLK) was constantly up-regulated. We investigated the evolutionary history of this gene and noticed it being one of the first to have emerged from a common ancestral gene that gave rise to a cluster of 11 genes through duplications. The encoded LRR-RLKs harbour an extracellular malectin-like (ML) domain in addition to a short stretch of leucine-rich repeats, and are thus similar to proteins from the symbiosis receptor-like kinase family. Detailed expression analysis showed that the pathogen-responsive gene was locally expressed in cells surrounding the oomycete. A knockout mutant showed reduced downy mildew infection, but susceptibility was fully restored through complementation of the mutation, suggesting that the (ML-)LRR-RLK contributes to disease. According to the mutant phenotype, we denominated it Impaired Oomycete Susceptibility 1 (IOS1).
authors.affiliation: Plant-Oomycete Interaction Group, UMR-Interactions Biotiques et Santé Végétale, INRA1301-CNRS6243-Université Nice-Sophia Antipolis, 06903, Sophia Antipolis, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Hok
authors.forename: Etienne G J
authors.initials: EG
authors.lastname: Danchin
authors.forename: Valérie
authors.initials: V
authors.lastname: Allasia
authors.forename: Franck
authors.initials: F
authors.lastname: Panabières
authors.forename: Agnès
authors.initials: A
authors.lastname: Attard
authors.forename: Harald
authors.initials: H
authors.lastname: Keller
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D032461:Chromosomes, Plant / Q000235:genetics; D004198:Disease Susceptibility; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D056426:Genetic Loci / Q000235:genetics; D054884:Host-Pathogen Interactions / Q000235:genetics; D000090263:Leucine-Rich Repeat Proteins; D005810:Multigene Family / Q000235:genetics; D044742:Peronospora / Q000502:physiology*; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology*; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D059467:Transcriptome; D015854:Up-Regulation / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D000090263:Leucine-Rich Repeat Proteins; D011506:Proteins; C569619:At1g51800 protein, Arabidopsis; D011494:Protein Kinases