United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, Tokyo 183-509, Japan.
J Microbiol. 2012 Aug;50(4):618-24. doi: 10.1007/s12275-012-2105-6. Epub 2012 Aug 25.
The soil-inhabiting fungal pathogen Fusarium oxysporum has been an increasing threat to Chinese cabbage (Brassica campestris L.). A dark septate endophytic fungus, Veronaeopsis simplex Y34, isolated from Yaku Island, Japan, was evaluated in vitro for the ability to suppress Fusarium disease. Seedlings grown in the presence of the endophyte showed a 71% reduction in Fusarium wilt disease and still had good growth. The disease control was achieved through a synergetic effect involving a mechanical resistance created by a dense network of V. simplex Y34 hyphae, which colonized the host root, and siderophore production acting indirectly to induce a resistance mechanism in the plant. Changes in the relative abundance of the fungal communities in the soil as determined by fluorescently labelled T-RFs (terminal restriction fragments), appeared 3 weeks after application of the fungus. Results showed the dominance of V. simplex Y34, which became established in the rhizosphere and out-competed F. oxysporum.
土壤内生真菌病原体尖孢镰刀菌（Fusarium oxysporum）对白菜（Brassica campestris L.）的威胁日益增加。从日本屋久岛分离得到的暗隔内生真菌 Veronaeopsis simplex Y34 被评估为抑制镰刀菌病的能力。在存在内生真菌的情况下生长的幼苗枯萎病发病率降低了 71%，且生长状况良好。这种病害防治是通过一种协同作用实现的，即由密集的 Veronaeopsis simplex Y34 菌丝网络形成的机械抗性，以及铁载体的产生间接作用，诱导植物产生抗性机制。接种真菌 3 周后，通过荧光标记 T-RFs（末端限制性片段）测定土壤中真菌群落的相对丰度发生了变化。结果表明，Veronaeopsis simplex Y34 占据优势地位，在根际定殖并与尖孢镰刀菌竞争。
