title: Detection and functional characterization of a large genomic deletion resulting in decreased pathogenicity in Ralstonia solanacearum race 3 biovar 2 strains.
abstract: Bacterial wilt (brown rot) disease of potato caused by Ralstonia solanacearum is one of the most important bacterial diseases and a major constraint on potato production worldwide. Through a comparative genomic analysis between R. solanacearum'race 3 biovar 2' (R3bv2) strains, we identified a 77 kb region in strain UW551 which is specifically absent in the hypoaggressive strain IPO1609. We proved that IPO1609 indeed carries a 77 kb genomic deletion and provide genetic evidence that occurrence of this deletion is responsible for almost complete loss of pathogenicity of this strain. We carried out a functional analysis of this 77 kb region in strain UW551 using a combination of gene deletion and functional complementation approaches which identified the methionine biosynthesis genes metER as having a major contribution to IPO1609 pathogenesis. Deletion of the metER genes significantly impacts pathogenicity of R3bv2 strains but does not lead to methionine auxotrophy nor reduced ability to multiply in planta. In addition, this study indicated that three type III secretion system effectors or a type VI secretion system present within the 77 kb region have no or very minor contribution to pathogenicity.
authors: Laboratoire des Interactions Plantes Micro-organismes (LIPM), UMR CNRS-INRA 2594/441, F- 31320 Castanet Tolosan, France.
authors: Adriana
authors: A
authors: González
authors: Laure
authors: L
authors: Plener
authors: Silvia
authors: S
authors: Restrepo
authors: Christian
authors: C
authors: Boucher
authors: Stéphane
authors: S
authors: Genin
mesh_terms: D058947:Bacterial Secretion Systems / Q000235:genetics; D001483:Base Sequence; D055028:Comparative Genomic Hybridization; D005816:Genetic Complementation Test; D016680:Genome, Bacterial; D023281:Genomics; D008715:Methionine / Q000096:biosynthesis; D008969:Molecular Sequence Data; D010641:Phenotype; D020161:Physical Chromosome Mapping; D010935:Plant Diseases / Q000382:microbiology*; D010957:Plasmids / Q000235:genetics; D043368:Ralstonia solanacearum / Q000235:genetics* / Q000472:pathogenicity; D017384:Sequence Deletion; D011198:Solanum tuberosum / Q000382:microbiology
chemical_list: D058947:Bacterial Secretion Systems; D008715:Methionine