title: Rhizoxin analogs contribute to the biocontrol activity of a newly isolated pseudomonas strain.
abstract: Two strains of Pseudomonas sp., Os17 and St29, were newly isolated from the rhizosphere of rice and potato, respectively, by screening for 2,4-diacetylphloroglucinol producers. These strains were found to be the same species and were the closest to but different from Pseudomonas protegens among the sequenced pseudomonads, based on 16S ribosomal RNA gene and whole-genome analyses. Strain Os17 was as effective a biocontrol agent as reported for P. protegens Cab57, whereas strain St29 was less effective. The whole-genome sequences of these strains were obtained: the genomes are organized into a single circular chromosome with 6,885,464 bp, 63.5% G+C content, and 6,195 coding sequences for strain Os17; and with 6,833,117 bp, 63.3% G+C content, and 6,217 coding sequences for strain St29. Comparative genome analysis of these strains revealed that the complete rhizoxin analog biosynthesis gene cluster (approximately 79 kb) found in the Os17 genome was absent from the St29 genome. In an rzxB mutant, which lacks the polyketide synthase essential for the production of rhizoxin analogs, the growth inhibition activity against fungal and oomycete pathogens and the plant protection efficacy were attenuated compared with those of wild-type Os17. These findings suggest that rhizoxin analogs are important biocontrol factors of this strain.
authors.forename: Kasumi
authors.initials: K
authors.lastname: Takeuchi
authors.forename: Naomi
authors.initials: N
authors.lastname: Noda
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Katayose
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mukai
authors.forename: Hisataka
authors.initials: H
authors.lastname: Numa
authors.forename: Kosumi
authors.initials: K
authors.lastname: Yamada
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Someya
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D000898:Antibiosis; D001407:Bacillus / Q000187:drug effects; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D061046:Biological Control Agents; D018553:Cucumis sativus / Q000382:microbiology*; D005670:Fusarium / Q000187:drug effects; D017930:Genes, Reporter; D016680:Genome, Bacterial / Q000235:genetics*; D018942:Macrolides / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D018517:Plant Roots / Q000382:microbiology; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism; D011549:Pseudomonas / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011775:Pythium / Q000187:drug effects; D011993:Recombinant Fusion Proteins; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D061046:Biological Control Agents; D018942:Macrolides; D011993:Recombinant Fusion Proteins; D048630:Polyketide Synthases; C059817:2,4-diacetylphloroglucinol; C041443:rhizoxin; D010696:Phloroglucinol