title: Characterization of the interaction between the bacterial wilt pathogen Ralstonia solanacearum and the model legume plant Medicago truncatula.
abstract: The soilborne pathogen Ralstonia solanacearum is the causal agent of bacterial wilt and attacks more than 200 plant species, including some legumes and the model legume plant Medicago truncatula. We have demonstrated that M. truncatula accessions Jemalong A17 and F83005.5 are susceptible to R. solanacearum and, by screening 28 R. solanacearum strains on the two M. truncatula lines, differential interactions were identified. R. solanacearum GMI1000 infected Jemalong A17 line, and disease symptoms were dependent upon functional hrp genes. An in vitro root inoculation method was employed to demonstrate that R. solanacearum colonized M. truncatula via the xylem and intercellular spaces. R. solanacearum multiplication was restricted by a factor greater than 1 x 10(5) in the resistant line F83005.5 compared with susceptible Jemalong A17. Genetic analysis of recombinant inbred lines from a cross between Jemalong A17 and F83005.5 revealed the presence of major quantitative trait loci for bacterial wilt resistance located on chromosome 5. The results indicate that the root pathosystem for M. truncatula will provide useful traits for molecular analyses of disease and resistance in this model plant species.
authors.affiliation: INP-ENSAT, Laboratoire de Biotechnologie et Amélioration des Plantes, BP32607, 31326 Castanet-Tolosan cedex, France. fabienne.vailleau@ensat.fr
authors.forename: Fabienne
authors.initials: F
authors.lastname: Vailleau
authors.forename: Elodie
authors.initials: E
authors.lastname: Sartorel
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Jardinaud
authors.forename: Fabien
authors.initials: F
authors.lastname: Chardon
authors.forename: Stéphane
authors.initials: S
authors.lastname: Genin
authors.forename: Thierry
authors.initials: T
authors.lastname: Huguet
authors.forename: Laurent
authors.initials: L
authors.lastname: Gentzbittel
authors.forename: Michel
authors.initials: M
authors.lastname: Petitprez
mesh_terms: D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D003433:Crosses, Genetic; D007113:Immunity, Innate / Q000235:genetics; D046913:Medicago truncatula / Q000235:genetics* / Q000382:microbiology; D018613:Microscopy, Confocal; D010935:Plant Diseases / Q000235:genetics* / Q000382:microbiology; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology; D040641:Quantitative Trait Loci / Q000235:genetics; D043368:Ralstonia solanacearum / Q000254:growth & development*; D013997:Time Factors; D052584:Xylem / Q000235:genetics / Q000382:microbiology