title: LYK4, a lysin motif receptor-like kinase, is important for chitin signaling and plant innate immunity in Arabidopsis.
abstract: Chitin is commonly found in fungal cell walls and is one of the well-studied microbe/pathogen-associated molecular patterns. Previous studies showed that lysin motif (LysM)-containing proteins are essential for plant recognition of chitin, leading to the activation of plant innate immunity. In Arabidopsis (Arabidopsis thaliana), the LYK1/CERK1 (for LysM-containing receptor-like kinase1/chitin elicitor receptor kinase1) was shown to be essential for chitin recognition, whereas in rice (Oryza sativa), the LysM-containing protein, CEBiP (for chitin elicitor-binding protein), was shown to be involved in chitin recognition. Unlike LYK1/CERK1, CEBiP lacks an intracellular kinase domain. Arabidopsis possesses three CEBiP-like genes. Our data show that mutations in these genes, either singly or in combination, did not compromise the response to chitin treatment. Arabidopsis also contains five LYK genes. Analysis of mutations in LYK2, -3, -4, or -5 showed that LYK4 is also involved in chitin signaling. The lyk4 mutants showed reduced induction of chitin-responsive genes and diminished chitin-induced cytosolic calcium elevation as well as enhanced susceptibility to both the bacterial pathogen Pseudomonas syringae pv tomato DC3000 and the fungal pathogen Alternaria brassicicola, although these phenotypes were not as dramatic as that seen in the lyk1/cerk1 mutants. Similar to LYK1/CERK1, the LYK4 protein was also localized to the plasma membrane. Therefore, LYK4 may play a role in the chitin recognition receptor complex to assist chitin signal transduction and plant innate immunity.
authors: Division of Plant Sciences, National Center for Soybean Biotechnology, Christopher S. Bond Life Sciences Center , University of Missouri, Columbia, Missouri 65211, USA.
authors: Jinrong
authors: J
authors: Wan
authors: Kiwamu
authors: K
authors: Tanaka
authors: Xue-Cheng
authors: XC
authors: Zhang
authors: Geon Hui
authors: GH
authors: Son
authors: Laurent
authors: L
authors: Brechenmacher
authors: Tran Hong Nha
authors: TH
authors: Nguyen
authors: Gary
authors: G
authors: Stacey
mesh_terms: D000528:Alternaria / Q000472:pathogenicity; D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D017796:Caulimovirus / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002686:Chitin / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism / Q000382:microbiology; D004198:Disease Susceptibility / Q000276:immunology / Q000382:microbiology; D004789:Enzyme Activation; D017343:Genes, Plant; D009154:Mutation; D010935:Plant Diseases / Q000276:immunology / Q000382:microbiology; D057865:Plant Immunity; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D044224:Pseudomonas syringae / Q000472:pathogenicity; D011956:Receptors, Cell Surface / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; D002686:Chitin; C525882:CERK1 protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; D002118:Calcium