title: Suppressive potential of Paenibacillus strains isolated from the tomato phyllosphere against fusarium crown and root rot of tomato.
abstract: The suppressive potentials of Bacillus and Paenibacillus strains isolated from the tomato phyllosphere were investigated to obtain new biocontrol candidates against Fusarium crown and root rot of tomato. The suppressive activities of 20 bacterial strains belonging to these genera were examined using seedlings and potted tomato plants, and two Paenibacillus strains (12HD2 and 42NP7) were selected as biocontrol candidates against the disease. These two strains suppressed the disease in the field experiment. Scanning electron microscopy revealed that the treated bacterial cells colonized the root surface, and when the roots of the seedlings were treated with strain 42NP7 cells, the cell population was maintained on the roots for at least for 4 weeks. Although the bacterial strains had no direct antifungal activity against the causal pathogen in vitro, an increase was observed in the antifungal activities of acetone extracts from tomato roots treated with the cells of both bacterial strains. Furthermore, RT-PCR analysis verified that the expression of defense-related genes was induced in both the roots and leaves of seedlings treated with the bacterial cells. Thus, the root-colonized cells of the two Paenibacillus strains were considered to induce resistance in tomato plants, which resulted in the suppression of the disease.
authors.affiliation: Environmental Biofunction Division, National Institute for Agro-Environmental Sciences.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Sato
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Yoshida
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: Masataka
authors.initials: M
authors.lastname: Aino
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Hyakumachi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Shimizu
authors.forename: Hideki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Sugihiro
authors.initials: S
authors.lastname: Ando
authors.forename: Seiya
authors.initials: S
authors.lastname: Tsushima
mesh_terms: D000898:Antibiosis; D001407:Bacillus / Q000302:isolation & purification / Q000502:physiology; D001483:Base Sequence; D061046:Biological Control Agents; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005670:Fusarium / Q000502:physiology*; D018551:Solanum lycopersicum / Q000166:cytology / Q000382:microbiology*; D056507:Paenibacillus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D010572:Pest Control, Biological; D010935:Plant Diseases / Q000382:microbiology*; D018515:Plant Leaves / Q000166:cytology / Q000382:microbiology; D018517:Plant Roots / Q000166:cytology / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D036226:Seedlings / Q000166:cytology / Q000382:microbiology; D017422:Sequence Analysis, DNA
chemical_list: D061046:Biological Control Agents; D018744:DNA, Plant; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S