title: LysM domain receptor kinases regulating rhizobial Nod factor-induced infection.
abstract: The rhizobial infection of legumes has the most stringent demand toward Nod factor structure of all host responses, and therefore a specific Nod factor entry receptor has been proposed. The SYM2 gene identified in certain ecotypes of pea (Pisum sativum) is a good candidate for such an entry receptor. We exploited the close phylogenetic relationship of pea and the model legume Medicago truncatula to identify genes specifically involved in rhizobial infection. The SYM2 orthologous region of M. truncatula contains 15 putative receptor-like genes, of which 7 are LysM domain-containing receptor-like kinases (LYKs). Using reverse genetics in M. truncatula, we show that two LYK genes are specifically involved in infection thread formation. This, as well as the properties of the LysM domains, strongly suggests that they are Nod factor entry receptors.
authors.affiliation: Laboratory of Molecular Biology, Department of Plant Sciences, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Limpens
authors.forename: Carolien
authors.initials: C
authors.lastname: Franken
authors.forename: Patrick
authors.initials: P
authors.lastname: Smit
authors.forename: Joost
authors.initials: J
authors.lastname: Willemse
authors.forename: Ton
authors.initials: T
authors.lastname: Bisseling
authors.forename: René
authors.initials: R
authors.lastname: Geurts
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015870:Gene Expression; D017343:Genes, Plant; D008024:Ligands; D008070:Lipopolysaccharides / Q000378:metabolism*; D029902:Medicago / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D009586:Nitrogen Fixation; D018532:Pisum sativum; D010641:Phenotype; D018517:Plant Roots / Q000382:microbiology* / Q000502:physiology; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D015398:Signal Transduction; D016962:Sinorhizobium meliloti / Q000737:chemistry / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D013559:Symbiosis
chemical_list: D008024:Ligands; D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides; D011494:Protein Kinases