Sato Ikuo, Yoshida Shigenobu, Iwamoto Yutaka, Aino Masataka, Hyakumachi Mitsuro, Shimizu Masafumi, Takahashi Hideki, Ando Sugihiro, Tsushima Seiya
Environmental Biofunction Division, National Institute for Agro-Environmental Sciences.
Microbes Environ. 2014;29(2):168-77. doi: 10.1264/jsme2.me13172. Epub 2014 Jun 10.
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.
为了获得防治番茄镰刀菌冠腐病和根腐病的新生物防治候选菌株，对从番茄叶际分离的芽孢杆菌属和类芽孢杆菌属菌株的抑制潜力进行了研究。使用番茄幼苗和盆栽番茄植株检测了属于这些属的20株细菌菌株的抑制活性，并选择了两株类芽孢杆菌菌株（12HD2和42NP7）作为该病害的生物防治候选菌株。在田间试验中，这两株菌株抑制了该病害。扫描电子显微镜显示，处理过的细菌细胞定殖在根表面，当用42NP7菌株细胞处理幼苗根部时，细胞群体在根部至少维持4周。虽然这些细菌菌株在体外对致病病原体没有直接的抗真菌活性，但在用这两种细菌菌株的细胞处理过的番茄根的丙酮提取物中，抗真菌活性有所增加。此外，RT-PCR分析证实，在用细菌细胞处理过的幼苗的根和叶中，与防御相关的基因表达均被诱导。因此，这两株类芽孢杆菌菌株定殖在根上的细胞被认为诱导了番茄植株的抗性，从而导致了病害的抑制。
