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Transmission mechanism of plant viruses transmitted by the fungus Polymyxa betae

甜菜多粘菌传播植物病毒的传播机制

基本信息

批准号：
09460028
负责人：
TAMADA Tetsuo
金额：
$ 7.04万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09460028/
关键词：
Plant viruses Benyvirus BNYVV Polymyxa Virus transmission Molecular biology Polymyxa菌ウイルスの伝搬 BNTVV

项目摘要

Beet necrotic yellow vein virus (BNYVV), which is transmitted by the soil-borne fungus Polymyxa betae, contains five ssRNA species (RNAs 1 to 5). BNYVV was transmitted by the biotype of P. batae from sugar beets, but not by the other biotypes from Chenopodium album, Amaranthus retroflexus and Portulaca oleracea. Although host ranges of BNYVV and the vector were thought to be limited to only few species such as Chenopdiaceae species, P. betae zoospores were found to infect a wide range of plant species, and also BNYVV infected roots of several plant species of them. Nicotiana benthamiana is a good indicator host. The coat protein is encoded by the 5' proximal ORF of RNA2, and the terminal codon of this ORF can be suppressed, which results in the production of a 75 kDa readthrough (RT) protein. Mutagenic analysis revealed that a region within the N-terminal half of the RT domain is involved in virus assembly, whereas the C-terminal protein contains sequences important for fungus transmission. Infectious cDNA clones to BNYVV RNAs 3,4 and 5 were established. Fungal inoculation tests with isolates containing different combinations of RNAs 3, 4 and 5 showed that RNA3 and RNA5 are involved in symptom expression. The 25 kDA protein encoded by RNA3 was responsible for rhizomania of susceptible cultivars of sugar beet, and also was involved in resistant reaction in resistant cultivars. When RNA5, encoding the 26 kDA protein, was present, the root symptoms were more intense, Antisera against 25 kDA AND 26 kDA protein, were obtained. It was suggested that expressions of these proteins in infected plant are strongly involved in symptom development. RNA4 was not associated with symptom expression, but acted as increasing transmission efficiency and stability. Synergistic effects were found between RNA4 and RNA3 or RNA5.

甜菜坏死黄脉病毒 (BNYVV) 由土传真菌多粘菌传播，包含 5 种 ssRNA（RNA 1 至 5）。 BNYVV 通过甜菜中的 P. batae 生物型传播，但不通过藜、反枝苋和马齿苋的其他生物型传播。尽管BNYVV和载体的宿主范围被认为仅限于藜科物种等少数物种，但发现P. betae游动孢子感染多种植物物种，并且BNYVV还感染其中几种植物物种的根部。本塞姆氏烟草是一个很好的指示宿主。外壳蛋白由 RNA2 的 5' 近端 ORF 编码，并且该 ORF 的末端密码子可以被抑制，从而产生 75 kDa 通读 (RT) 蛋白。诱变分析表明，RT 结构域 N 端一半内的区域参与病毒组装，而 C 端蛋白包含对真菌传播重要的序列。建立了 BNYVV RNA 3,4 和 5 的感染性 cDNA 克隆。对含有不同 RNA 3、4 和 5 组合的分离株进行真菌接种试验表明，RNA3 和 RNA5 参与症状表达。 RNA3编码的25 kDA蛋白与感病品种甜菜根茎病有关，也参与抗性品种的抗性反应。当编码26 kDA蛋白的RNA5存在时，根部症状更加强烈，获得针对25 kDA和26 kDA蛋白的抗血清。有人认为，这些蛋白质在受感染植物中的表达与症状的发展密切相关。 RNA4与症状表达无关，但可以提高传播效率和稳定性。在RNA4和RNA3或RNA5之间发现了协同效应。