title: The virulence of a Dickeya dadantii 3937 mutant devoid of osmoregulated periplasmic glucans is restored by inactivation of the RcsCD-RcsB phosphorelay.
abstract: Dickeya dadantii is a pectinolytic phytopathogen enterobacterium that causes soft rot disease on a wide range of plant species. The virulence of D. dadantii involves several factors, including the osmoregulated periplasmic glucans (OPGs) that are general constituents of the envelope of proteobacteria. In addition to the loss of virulence, opg-negative mutants display a pleiotropic phenotype, including decreased motility and increased exopolysaccharide synthesis. A nitrosoguanidine-induced mutagenesis was performed on the opgG strain, and restoration of motility was used as a screen. The phenotype of the opg mutant echoes that of the Rcs system: high level activation of the RcsCD-RcsB phosphorelay is needed to activate exopolysaccharide synthesis and to repress motility, while low level activation is required for virulence in enterobacteria. Here, we show that mutations in the RcsCDB phosphorelay system restored virulence and motility in a D. dadantii opg-negative strain, indicating a relationship between the Rcs phosphorelay and OPGs.
authors.affiliation: Université des Sciences et Technologies de Lille, Unité de Glycobiologie Structurale et Fonctionnelle, UMR USTL-CNRS 8576 IFR147, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Bouchart
authors.forename: Gilles
authors.initials: G
authors.lastname: Boussemart
authors.forename: Anne-France
authors.initials: AF
authors.lastname: Prouvost
authors.forename: Virginie
authors.initials: V
authors.lastname: Cogez
authors.forename: Edwige
authors.initials: E
authors.lastname: Madec
authors.forename: Olivier
authors.initials: O
authors.lastname: Vidal
authors.forename: Brigitte
authors.initials: B
authors.lastname: Delrue
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bohin
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Lacroix
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D018651:Cichorium intybus / Q000382:microbiology; D004755:Enterobacteriaceae / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics / Q000502:physiology; D005936:Glucans / Q000378:metabolism*; D016296:Mutagenesis; D019897:Periplasm / Q000378:metabolism*; D011198:Solanum tuberosum / Q000382:microbiology; D014774:Virulence / Q000235:genetics / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D005936:Glucans