title: The Medicago truncatula lysin [corrected] motif-receptor-like kinase gene family includes NFP and new nodule-expressed genes.
abstract: Rhizobial Nod factors are key symbiotic signals responsible for starting the nodulation process in host legume plants. Of the six Medicago truncatula genes controlling a Nod factor signaling pathway, Nod Factor Perception (NFP) was reported as a candidate Nod factor receptor gene. Here, we provide further evidence for this by showing that NFP is a lysin [corrected] motif (LysM)-receptor-like kinase (RLK). NFP was shown both to be expressed in association with infection thread development and to be involved in the infection process. Consistent with deviations from conserved kinase domain sequences, NFP did not show autophosphorylation activity, suggesting that NFP needs to associate with an active kinase or has unusual functional characteristics different from classical kinases. Identification of nine new M. truncatula LysM-RLK genes revealed a larger family than in the nonlegumes Arabidopsis (Arabidopsis thaliana) or rice (Oryza sativa) of at least 17 members that can be divided into three subfamilies. Three LysM domains could be structurally predicted for all M. truncatula LysM-RLK proteins, whereas one subfamily, which includes NFP, was characterized by deviations from conserved kinase sequences. Most of the newly identified genes were found to be expressed in roots and nodules, suggesting this class of receptors may be more extensively involved in nodulation than was previously known.
authors.affiliation: Laboratoire des Interactions Plantes-Microorganismes, Institut National de la Recherche Agronomique-Centre National de la Recherche Scientifique, Unité Mixte de Recherche 441/2594, 31326 Castanet-Tolosan, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Arrighi
authors.forename: Annick
authors.initials: A
authors.lastname: Barre
authors.forename: Besma
authors.initials: B
authors.lastname: Ben Amor
authors.forename: Anne
authors.initials: A
authors.lastname: Bersoult
authors.forename: Lidia Campos
authors.initials: LC
authors.lastname: Soriano
authors.forename: Rossana
authors.initials: R
authors.lastname: Mirabella
authors.forename: Fernanda
authors.initials: F
authors.lastname: de Carvalho-Niebel
authors.forename: Etienne-Pascal
authors.initials: EP
authors.lastname: Journet
authors.forename: Michèle
authors.initials: M
authors.lastname: Ghérardi
authors.forename: Thierry
authors.initials: T
authors.lastname: Huguet
authors.forename: René
authors.initials: R
authors.lastname: Geurts
authors.forename: Jean
authors.initials: J
authors.lastname: Dénarié
authors.forename: Pierre
authors.initials: P
authors.lastname: Rougé
authors.forename: Clare
authors.initials: C
authors.lastname: Gough
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D020440:Gene Duplication; D015870:Gene Expression; D018745:Genome, Plant; D008239:Lysine / Q000737:chemistry; D046913:Medicago truncatula / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010766:Phosphorylation; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D016962:Sinorhizobium meliloti / Q000502:physiology*; D013559:Symbiosis / Q000235:genetics / Q000502:physiology
chemical_list: D010940:Plant Proteins; D011494:Protein Kinases; D008239:Lysine