Studies on pathoigenicity mechanism of Ralstonia solanacearum and disease development of bacterial wilt

青枯雷尔斯顿菌致病机制及青枯病发生规律研究

• 批准号: 12660047
• 负责人: HIKICHI Yasufumi
• 金额: $ 2.3万
• 依托单位: Kochi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12660047/
• 关键词: Bacterial wilt; Ralstonia solanacearum; PopA protein; 病原性; 相互作用

Ralstonia solanacearum OE1-1 (OE1-1) is pathogenic to tobacco. A popA-mutant of OE1-1 with Tn4431, 31b, grew in and moved through vascular bundle in tabacco but lost its pathogenicity to the tobacco plants, when inoculated by root dipping and infiltrated into tobacco leaves. However, the mutant showed pathogenicity to the tobacco plants inoculated into vascular bundle through cut stems. The mutated PopA protein of 31b was composed of 319 amino acid residues, and the amino acid sequence of 1-307 residues was identical to that of PopA protein of OE1-1. A popABC operon-deleted mutant of OE1-1, △ABC-OE, showed pathogenicity similarly as the parent strain. On the other hand, a transformant, △OE-p31b, of △ABC-OE with p31b including a mutated popA showed pathogenicity similarly as 31b. The analysis of RT-PCR showed that popA in OE1-1 was expressed 3 hr after infiltration with into tobacco leaves (HIT), and mutated popA in 31b and △OE-p31b was also expressed 3 HIT. When a transformant of OE1-1 … More , Papa with pPapa containing popA fused to a constitutively active promoter infiltrated into tobacco leaves, popA was expressed 1 HAI. Papa did not grow in inoculated area and move to periphery, resulting in loss of its pathogenicity to tobacco plants when inoculated using the root dipping and infiltrated into tobacco leaves. However, Papa retained its pathogenicity when directly inoculated into vascular bundle. These results indicate that PopA protein is not directly involved in the bacterial pathogenicity because popA is not expressed until 3 HAI. However, when popA is expressed 1 HAI, PopA can function as a negative effector of the bacterial proliferation in the host plants, resulting in loss of the bacterial pathogenicity. Moreover, C-terminus-mutated PopA protein makes influences on the bacteria-plant interactions from 3 HAI to the bacterial arrival to vascular bundle, resulting in negative regulation on the bacterial pathogenicity. Taken together, the bacterial proliferation and movement into vascular bundle immediately after invasion, which are essential factors of its pathogenicity, depend on interactions between R solariacearum and host plants during 3 hr after the bacterial invasion Moreover, development of wilt symptom depends on the interactions in intercellular spaces of roots and mesophyll until the bacterial infection to vascular bundle. Less

茄酸Ralstonia solanacearum OE1-1 （OE1-1）对烟草具有致病性。带有tn4431,31b的popa突变体OE1-1在烟草维管束中生长并通过维管束移动，但通过根浸接种并渗入烟草叶片后失去了对烟草植株的致病性。而该突变体对通过切茎接种维管束的烟草植株表现出致病性。突变的31b PopA蛋白由319个氨基酸残基组成，其中1-307个残基的氨基酸序列与OE1-1的PopA蛋白相同。OE1-1的popABC开子缺失突变株△ABC-OE表现出与亲本菌株相似的致病性。另一方面，含有突变popA的p31b的△ABC-OE的突变体△OE-p31b表现出与31b相似的致病性。RT-PCR分析显示，OE1-1在侵染烟叶（HIT）后3小时表达popA，突变的31b和△e -p31b也在侵染烟叶后3小时表达popA。当OE1-1…More， Papa与含有popA的pPapa的转化融合到一个组成活性启动子渗透到烟叶中时，popA表达为1hai。棒棒菌不在接种区生长，向周边移动，导致其根浸接种时对烟草植株丧失致病性，渗入烟叶。而直接接种于维管束时，Papa仍具有致病性。这些结果表明PopA蛋白并不直接参与细菌的致病性，因为PopA直到3 HAI才表达。然而，当popA表达1 HAI时，popA可在寄主植物中作为细菌增殖的负效应因子，导致细菌致病性丧失。此外，c端突变的PopA蛋白从3hai到细菌到达维管束都对细菌与植物的相互作用产生影响，从而对细菌的致病性产生负调控。综上所述，细菌入侵后立即进入维管束的增殖和运动是其致病性的重要因素，这取决于细菌入侵后3小时内与寄主植物的相互作用，而枯萎症状的发展取决于根和叶肉细胞间隙的相互作用，直到细菌侵染维管束。少

项目成果

土屋健一,堀田光生,曵地康史: "最近の青枯病の話題と問題点"植物防疫. 54巻. 87-92 (2000)

Kenichi Tsuchiya、Mitsuo Hotta、Yasushi Hikichi：“有关青枯病的最新主题和问题”《植物保护》卷 54. 87-92 (2000)。

Hikichi, Y., Kanda, A., Takahashi, H., Yasukochi, Y., Nakazawa-Nasu. Y., Suzuki, K. and Okuno, T.: "Plant-Microbe Interactions which determine pathogenicity of Ralstonia solanacearum"Soilborne Disease Workshop Report. 20. 46-66 (2000)

Hikichi, Y.、Kanda, A.、Takahashi, H.、Yasukochi, Y.、Nakazawa-Nasu。

Hikichi, Y., Kanda, A., Hasegawa, H., Kitanosono, S., Ikegami, M., Takahashi, H., Yoshii, M. and Okuno, T.: "Pathogenicity mechanisms of Ralstonia solanacearum"Plant-Microbe Interactions Symposium Reports. 36. 46-55 (2000)

Hikichi, Y.、Kanda, A.、Hasekawa, H.、Kitanosono, S.、Ikegami, M.、Takahashi, H.、Yoshii, M. 和 Okuno, T.：“青枯雷尔斯顿氏菌的致病机制”植物微生物

曵地康史: "青枯病菌の病原性を決定する宿主植物との相互作用"土壌伝染病談話会レポート. 20号. 46-56 (2000)

Yasushi Hikichi：“与宿主植物的相互作用决定青枯病真菌的致病性”土壤传播疾病论坛报告第 20. 46-56 号（2000 年）。

Kanda, A., Hasegawa, H., Takahashi, H., Hikichi, Y., Okuno, T.: "Roles of popA for the pathogenicity of Ralstonia solanacearum pathogenic to tobacco"Proceedings of the 10th International Conference on Plant Pathogenic Bacteria. 233-236 (2001)

Kanda, A.、Hasekawa, H.、Takahashi, H.、Hikichi, Y.、Okuno, T.：“popA 对烟草致病性青枯菌致病性的作用”第十届植物病原细菌国际会议论文集。