title: Transcriptome analysis of the Dickeya dadantii PecS regulon during the early stages of interaction with Arabidopsis thaliana.
abstract: PecS is one of the major global regulators controlling the virulence of Dickeya dadantii, a broad-host-range phytopathogenic bacterium causing soft rot on several plant families. To define the PecS regulon during plant colonization, we analysed the global transcriptome profiles in wild-type and pecS mutant strains during the early colonization of the leaf surfaces and in leaf tissue just before the onset of symptoms, and found that the PecS regulon consists of more than 600 genes. About one-half of these genes are down-regulated in the pecS mutant; therefore, PecS has both positive and negative regulatory roles that may be direct or indirect. Indeed, PecS also controls the regulation of a few dozen regulatory genes, demonstrating that this global regulator is at or near the top of a major regulatory cascade governing adaptation to growth in planta. Notably, PecS acts mainly at the very beginning of infection, not only to prevent virulence gene induction, but also playing an active role in the adaptation of the bacterium to the epiphytic habitat. Comparison of the patterns of gene expression inside leaf tissues and during early colonization of leaf surfaces in the wild-type bacterium revealed 637 genes modulated between these two environments. More than 40% of these modulated genes are part of the PecS regulon, emphasizing the prominent role of PecS during plant colonization.
authors.affiliation: Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France.|iEES (Institut d'Ecologie et des Sciences de l'Environnement de Paris), Sorbonne Universités, UPMC Université Paris 06, Diderot Université Paris 07, UPEC Université Paris 12, CNRS, INRA, IRD, Paris, 75005, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Pédron
authors.affiliation: Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Chapelle
authors.affiliation: Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France.|Institute for Integrative Biology of the Cell, UMR 9198, CNRS/Universite Paris-Sud/CEA, Gif-sur-Yvette, 91198, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Alunni
authors.affiliation: Interactions Plantes Pathogènes, AgroParisTech, INRA, UPMC Université Paris 06, Paris, 75005, France.|iEES (Institut d'Ecologie et des Sciences de l'Environnement de Paris), Sorbonne Universités, UPMC Université Paris 06, Diderot Université Paris 07, UPEC Université Paris 12, CNRS, INRA, IRD, Paris, 75005, France.
authors.forename: Frédérique
authors.initials: F
authors.lastname: Van Gijsegem
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004755:Enterobacteriaceae / Q000472:pathogenicity*; D020869:Gene Expression Profiling / Q000379:methods*; D018085:Regulon / Q000235:genetics / Q000502:physiology; D014774:Virulence / Q000235:genetics / Q000502:physiology
chemical_list: D001426:Bacterial Proteins
keywords: Arabidopsis; Dickeya dadantii; T6SS; epiphytic colonization; in planta transcriptome; regulatory networks; virulence