title: Rice Bran Amendment Suppresses Potato Common Scab by Increasing Antagonistic Bacterial Community Levels in the Rhizosphere.
abstract: Potato common scab (PCS), caused by pathogenic Streptomyces spp., is a serious disease in potato production worldwide. Cultural practices, such as optimizing the soil pH and irrigation, are recommended but it is often difficult to establish stable disease reductions using these methods. Traditionally, local farmers in southwest Japan have amended soils with rice bran (RB) to suppress PCS. However, the scientific mechanism underlying disease suppression by RB has not been elucidated. The present study showed that RB amendment reduced PCS by repressing the pathogenic Streptomyces population in young tubers. Amplicon sequencing analyses of 16S ribosomal RNA genes from the rhizosphere microbiome revealed that RB amendment dramatically changed bacterial composition and led to an increase in the relative abundance of gram-positive bacteria such as Streptomyces spp., and this was negatively correlated with PCS disease severity. Most actinomycete isolates derived from the RB-amended soil showed antagonistic activity against pathogenic Streptomyces scabiei and S. turgidiscabies on R2A medium. Some of the Streptomyces isolates suppressed PCS when they were inoculated onto potato plants in a field experiment. These results suggest that RB amendment increases the levels of antagonistic bacteria against PCS pathogens in the potato rhizosphere.
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tomihama
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Yatsuka
authors.initials: Y
authors.lastname: Nishi
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Mori
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Shirao
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Iida
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Shihomi
authors.initials: S
authors.lastname: Uzuhashi
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Moriya
authors.initials: M
authors.lastname: Ohkuma
authors.affiliation: First, second, third, and fourth authors: Plant Pathology and Entomology Laboratory, Kagoshima Prefectural Institute for Agricultural Development, 2200 Oono, Kinpo-cho, Minamikyushu-shi, Kagoshima, 899-3401, Japan; fifth, sixth, and seventh authors: Japan Collection of Microorganisms/Microbe Division, RIKEN BioResource Center, 3-1-1 Kounodai, Tsukuba, Ibaragi, 305-0074, Japan; and eighth author: Agricultural Research Center for Hokkaido, National Agricultural and Food Research Organization, 9-4 Shinsei-minami, Memuro, Kasai, Hokkaido 082-0081, Japan.
authors.forename: Seishi
authors.initials: S
authors.lastname: Ikeda
mesh_terms: D039903:Actinobacteria / Q000502:physiology; D000383:Agriculture / Q000379:methods*; D000898:Antibiosis; D054884:Host-Pathogen Interactions; D012275:Oryza; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology / Q000517:prevention & control*; D035281:Plant Tubers / Q000382:microbiology; D012988:Soil Microbiology; D011198:Solanum tuberosum / Q000382:microbiology*; D013302:Streptomyces / Q000502:physiology*
keywords: rhizosphere bacterial community