title: Characterization of Cichopeptins, New Phytotoxic Cyclic Lipodepsipeptides Produced by Pseudomonas cichorii SF1-54 and Their Role in Bacterial Midrib Rot Disease of Lettuce.
abstract: The lettuce midrib rot pathogen Pseudomonas cichorii SF1-54 produces seven bioactive compounds with biosurfactant properties. Two compounds exhibited necrosis-inducing activity on chicory leaves. The structure of the two phytotoxic compounds, named cichopeptin A and B, was tentatively characterized. They are related cyclic lipopeptides composed of an unsaturated C12-fatty acid chain linked to the N-terminus of a 22-amino acid peptide moiety. Cichopeptin B differs from cichopeptin A only in the last C-terminal amino acid residue, which is probably Val instead of Leu/Ile. Based on peptide sequence similarity, cichopeptins are new cyclic lipopeptides related to corpeptin, produced by the tomato pathogen Pseudomonas corrugata. Production of cichopeptin is stimulated by glycine betaine but not by choline, an upstream precursor of glycine betaine. Furthermore, a gene cluster encoding cichopeptin synthethases, cipABCDEF, is responsible for cichopeptin biosynthesis. A cipA-deletion mutant exhibited significantly less virulence and rotten midribs than the parental strain upon spray inoculation on lettuce. However, the parental and mutant strains multiplied in lettuce leaves at a similar rate. These results demonstrate that cichopeptins contribute to virulence of P. cichorii SF1-54 on lettuce.
authors.affiliation: 1 Department of Crop Protection, Laboratory of Phytopathology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium;|2 Department of Plant Medicine, National Chiayi University, No. 300, Syuefu Rd., Chiayi City, 60004, Taiwan (R.O.C.);
authors.forename: Chien-Jui
authors.initials: CJ
authors.lastname: Huang
authors.affiliation: 1 Department of Crop Protection, Laboratory of Phytopathology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium;|3 Inagro vzw, Ieperseweg 87, 8800 Rumbeke, Belgium;
authors.forename: Ellen
authors.initials: E
authors.lastname: Pauwelyn
authors.affiliation: 4 Walloon Centre for Industrial Biology, University of Liège-Gembloux Agro-Bio Tech, Passage des Déportés 2, 5030 Gembloux, Belgium;
authors.forename: Marc
authors.initials: M
authors.lastname: Ongena
authors.affiliation: 5 Mass Spectrometry Laboratory (LSM/GIGA-R), Chemistry Department, University of Liege, 4000 Liege, Belgium;
authors.forename: Delphine
authors.initials: D
authors.lastname: Debois
authors.affiliation: 6 Laboratoire de Procédés Biologiques, Génie Enzymatique et Microbien (ProBioGEM), Université de Lille Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Valerie
authors.initials: V
authors.lastname: Leclère
authors.affiliation: 6 Laboratoire de Procédés Biologiques, Génie Enzymatique et Microbien (ProBioGEM), Université de Lille Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacques
authors.affiliation: 3 Inagro vzw, Ieperseweg 87, 8800 Rumbeke, Belgium;
authors.forename: Peter
authors.initials: P
authors.lastname: Bleyaert
authors.affiliation: 1 Department of Crop Protection, Laboratory of Phytopathology, Ghent University, Coupure Links 653, 9000 Ghent, Belgium;
authors.forename: Monica
authors.initials: M
authors.lastname: Höfte
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D018545:Lactuca / Q000382:microbiology*; D055666:Lipopeptides / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology*; D011549:Pseudomonas / Q000145:classification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D055666:Lipopeptides