title: Identification and characterization of nodulation-signaling pathway 2, a gene of Medicago truncatula involved in Nod actor signaling.
abstract: Bacterially derived Nod factor is critical in the establishment of the legume/rhizobia symbiosis. Understanding the mechanisms of Nod factor perception and signal transduction in the plant will greatly advance our understanding of this complex interaction. Here, we describe the identification of a new locus, nodulation-signaling pathway 2 (NSP2), of Medicago truncatula that is involved in Nod factor signaling. Mutants at this locus are blocked for Nod factor-induced gene expression and show a reduced root hair deformation response. nsp2 plants also show a complete absence of infection and cortical cell division following Sinorhizobium meliloti inoculation. Nod factor-induced calcium spiking, one of the earliest responses tested, is still functional in these mutant plants. We conclude that the gene NSP2 is a component of the Nod factor signal transduction pathway that lies downstream of the calcium-spiking response.
authors.affiliation: Department of Biological Sciences, Stanford University, Stanford, California 94305-5020, USA.
authors.forename: Giles E D
authors.initials: GE
authors.lastname: Oldroyd
authors.forename: Sharon R
authors.initials: SR
authors.lastname: Long
mesh_terms: D002118:Calcium / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008040:Genetic Linkage; D008070:Lipopolysaccharides / Q000494:pharmacology*; D029902:Medicago / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008938:Mitosis / Q000187:drug effects / Q000235:genetics; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology; D015398:Signal Transduction / Q000235:genetics* / Q000502:physiology; D016962:Sinorhizobium meliloti / Q000254:growth & development*
chemical_list: D008070:Lipopolysaccharides; C489058:MTN6 protein, Medicago truncatula; D008565:Membrane Proteins; C092082:Nod factor IV, Rhizobium meliloti; D010940:Plant Proteins; C045625:nodulin; D002118:Calcium