title: Concentration of osmoregulated periplasmic glucans (OPGs) modulates the activation level of the RcsCD RcsB phosphorelay in the phytopathogen bacteria Dickeya dadantii.
abstract: Osmoregulated periplasmic glucans (OPGs) are general constituents of many Proteobacteria. Synthesis of these oligosaccharides is repressed by increased osmolarity of the medium. OPGs are important factors required for full virulence in many zoo- or phytopathogens including Dickeya dadantii. The phytopathogen enterobacterium D. dadantii causes soft-rot disease on a wide range of plant species. The total loss of virulence of opg-negative strains of D. dadantii is linked to the constitutive activation of the RcsCD RcsB phosphorelay highlighting relationship between this phosphorelay and OPGs. Here we show that OPGs control the RcsCD RcsB activation in a concentration-dependent manner, are required for proper activation of this phosphorelay by medium osmolarity, and a high concentration of OPGs in planta is maintained to achieve the low level of activation of the RcsCD RcsB phosphorelay required for full virulence in D. dadantii.
authors.affiliation: Unité de Glycobiologie Structurale et Fonctionnelle, UMR CNRS 8576, IFR 147, Université des Sciences et Technologies de Lille, 59655, Villeneuve d'Ascq, France.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Bontemps-Gallo
authors.forename: Edwige
authors.initials: E
authors.lastname: Madec
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Dondeyne
authors.forename: Brigitte
authors.initials: B
authors.lastname: Delrue
authors.forename: Catherine
authors.initials: C
authors.lastname: Robbe-Masselot
authors.forename: Olivier
authors.initials: O
authors.lastname: Vidal
authors.forename: Anne-France
authors.initials: AF
authors.lastname: Prouvost
authors.forename: Gilles
authors.initials: G
authors.lastname: Boussemart
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Bohin
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Lacroix
mesh_terms: D001089:Arabinose / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D004755:Enterobacteriaceae / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D015964:Gene Expression Regulation, Bacterial; D005936:Glucans / Q000235:genetics / Q000378:metabolism*; D009994:Osmolar Concentration; D064587:Osmoregulation / Q000502:physiology; D019897:Periplasm / Q000378:metabolism; D010944:Plants / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D005936:Glucans; D001089:Arabinose