title: Surface polysaccharides and quorum sensing are involved in the attachment and survival of Xanthomonas albilineans on sugarcane leaves.
abstract: Xanthomonas albilineans, the causal agent of sugarcane leaf scald, is a bacterial plant pathogen that is mainly spread by infected cuttings and contaminated harvesting tools. However, some strains of this pathogen are known to be spread by aerial means and are able to colonize the phyllosphere of sugarcane before entering the host plant and causing disease. The objective of this study was to identify the molecular factors involved in the survival or growth of X. albilineans on sugarcane leaves. We developed a bioassay to test for the attachment of X. albilineans on sugarcane leaves using tissue-cultured plantlets grown in vitro. Six mutants of strain XaFL07-1 affected in surface polysaccharide production completely lost their capacity to survive on the sugarcane leaf surface. These mutants produced more biofilm in vitro and accumulated more cellular poly-β-hydroxybutyrate than the wild-type strain. A mutant affected in the production of small molecules (including potential biosurfactants) synthesized by non-ribosomal peptide synthetases (NRPSs) attached to the sugarcane leaves as well as the wild-type strain. Surprisingly, the attachment of bacteria on sugarcane leaves varied among mutants of the rpf gene cluster involved in bacterial quorum sensing. Therefore, quorum sensing may affect polysaccharide production, or both polysaccharides and quorum sensing may be involved in the survival or growth of X. albilineans on sugarcane leaves.
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.
authors.forename: Imene
authors.initials: I
authors.lastname: Mensi
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.
authors.forename: Jean-Heinrich
authors.initials: JH
authors.lastname: Daugrois
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pieretti
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Gargani
authors.affiliation: Plant Pathology Department, University of Florida, Gainesville, 32611, USA.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Fleites
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Noell
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Bonnot
authors.affiliation: Plant Pathology Department, University of Florida, Gainesville, 32611, USA.
authors.forename: Dean W
authors.initials: DW
authors.lastname: Gabriel
authors.affiliation: UMR BGPI, CIRAD, F-34398, Montpellier, France.|Plant Pathology Department, University of Florida, Gainesville, 32611, USA.
authors.forename: Philippe
authors.initials: P
authors.lastname: Rott
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms; D001681:Biological Assay; D006885:Hydroxybutyrates; D050296:Microbial Viability; D005810:Multigene Family; D009154:Mutation / Q000235:genetics; D009930:Organic Chemicals; D010453:Peptide Synthases / Q000378:metabolism; D018515:Plant Leaves / Q000382:microbiology*; D010957:Plasmids / Q000378:metabolism; D011091:Polyesters; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D053038:Quorum Sensing; D031786:Saccharum / Q000382:microbiology*; D013499:Surface Properties; D014974:Xanthomonas / Q000235:genetics / Q000254:growth & development / Q000502:physiology* / Q000648:ultrastructure; D000094122:Polyhydroxybutyrates
chemical_list: D006885:Hydroxybutyrates; D009930:Organic Chemicals; D010453:Peptide Synthases; D011091:Polyesters; D011135:Polysaccharides, Bacterial; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates; C046156:albicidin; C104385:non-ribosomal peptide synthase
keywords: NRPS; Xanthomonas albilineans.; biofilm; quorum sensing; rpf genes; sugarcane; surface polysaccharides