title: Competitiveness in root colonization by Pseudomonas putida requires the rpoS gene.
abstract: The rpoS gene in Pseudomonas putida was essential for plant root colonization under competitive conditions from other microbes. The RpoS- mutant survived less well than the wild-type strain in culture medium, and unlike the wild-type, failed to colonize the roots in a peat matrix containing an established diverse microflora. The RpoS-deficient P. putida isolate was generated by insertion of a glucuronidase-npt cassette into the rpoS gene. The RpoS mutant had dose-dependent increased sensitivity to oxidative stress and produced Mn-superoxide dismutase activity earlier than the parent. While extracts from wild-type P. putida stationary-phase cells contained three isozymes of catalase (CatA, CatB, and CatC), the sigma38-deficient P. putida lacked CatB. These results are consistent with previous findings that CatB is induced in stationary-phase.
authors.affiliation: Department of Biology, Utah State University, Logan, UT 84522-5305, USA.
authors.forename: C D
authors.initials: CD
authors.lastname: Miller
authors.forename: Y C
authors.initials: YC
authors.lastname: Kim
authors.forename: A J
authors.initials: AJ
authors.lastname: Anderson
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*; D002374:Catalase / Q000096:biosynthesis; D015169:Colony Count, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D017353:Gene Deletion; D005798:Genes, Bacterial; D006861:Hydrogen Peroxide / Q000378:metabolism; D016254:Mutagenesis, Insertional; D018384:Oxidative Stress; D018517:Plant Roots / Q000382:microbiology*; D016958:Pseudomonas putida / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D012808:Sigma Factor / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D012988:Soil Microbiology; D013482:Superoxide Dismutase / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase