title: The Novel Lipopeptide Poaeamide of the Endophyte Pseudomonas poae RE*1-1-14 Is Involved in Pathogen Suppression and Root Colonization.
abstract: Endophytic Pseudomonas poae strain RE*1-1-14 was originally isolated from internal root tissue of sugar beet plants and shown to suppress growth of the fungal pathogen Rhizoctonia solani both in vitro and in the field. To identify genes involved in its biocontrol activity, RE*1-1-14 random mutagenesis and sequencing led to the identification of a nonribosomal peptide synthetase (NRPS) gene cluster predicted to encode a lipopeptide (LP) with a 10-amino-acid peptide moiety. The two unlinked gene clusters consisted of three NRPS genes, designated poaA (cluster 1) and poaB and poaC (cluster 2), spanning approximately 33.7 kb. In silico analysis followed by chemical analyses revealed that the encoded LP, designated poaeamide, is a structurally new member of the orfamide family. Poaeamide inhibited mycelial growth of R. solani and different oomycetes, including Phytophthora capsici, P. infestans, and Pythium ultimum. The novel LP was shown to be essential for swarming motility of strain RE*1-1-14 and had an impact on root colonization of sugar beet seedlings The poaeamide-deficient mutant colonized the rhizosphere and upper plant cortex at higher densities and with more scattered colonization patterns than the wild type. Collectively, these results indicate that Pseudomonas poae RE*1-1-14 produces a structurally new LP that is relevant for its antagonistic activity against soilborne plant pathogens and for colonization of sugar beet roots.
authors.affiliation: 1 Austrian Centre of Industrial Biotechnology (ACIB GmbH), 8010 Graz, Austria;
authors.forename: Christin
authors.initials: C
authors.lastname: Zachow
authors.affiliation: 2 Pharmaceutical Institute, Department of Pharmaceutical Biology, University of Tübingen, 72076 Tübingen, Germany;
authors.forename: Ghazaleh
authors.initials: G
authors.lastname: Jahanshah
authors.affiliation: 3 Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands;
authors.forename: Irene
authors.initials: I
authors.lastname: de Bruijn
authors.affiliation: 3 Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands;
authors.forename: Chunxu
authors.initials: C
authors.lastname: Song
authors.affiliation: 4 Pharmaceutical Institute, Department of Pharmaceutical Analysis and Bioanalysis, University of Tübingen;
authors.forename: Federica
authors.initials: F
authors.lastname: Ianni
authors.affiliation: 4 Pharmaceutical Institute, Department of Pharmaceutical Analysis and Bioanalysis, University of Tübingen;
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Pataj
authors.affiliation: 4 Pharmaceutical Institute, Department of Pharmaceutical Analysis and Bioanalysis, University of Tübingen;
authors.forename: Heike
authors.initials: H
authors.lastname: Gerhardt
authors.affiliation: 5 CESAMO-ISM, UMR 5255, CNRS, Université Bordeaux I, 351 Cours de la Libération, F-33405 Talence, France;
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pianet
authors.affiliation: 4 Pharmaceutical Institute, Department of Pharmaceutical Analysis and Bioanalysis, University of Tübingen;
authors.forename: Michael
authors.initials: M
authors.lastname: Lämmerhofer
authors.affiliation: 6 Institute of Environmental Biotechnology, Graz University of Technology, 8010 Graz, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Berg
authors.affiliation: 2 Pharmaceutical Institute, Department of Pharmaceutical Biology, University of Tübingen, 72076 Tübingen, Germany;
authors.forename: Harald
authors.initials: H
authors.lastname: Gross
authors.affiliation: 3 Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, 6708 PB Wageningen, The Netherlands;
authors.forename: Jos M
authors.initials: JM
authors.lastname: Raaijmakers
mesh_terms: D000898:Antibiosis; D027461:Beta vulgaris / Q000382:microbiology; D060026:Endophytes / Q000502:physiology*; D054884:Host-Pathogen Interactions; D055666:Lipopeptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D005810:Multigene Family; D009154:Mutation; D009868:Oomycetes / Q000187:drug effects / Q000254:growth & development; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism*; D012232:Rhizoctonia / Q000187:drug effects / Q000472:pathogenicity*; D058441:Rhizosphere
chemical_list: D055666:Lipopeptides