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Transmission mechanism of Benyvirus (BNYVV) by the fungus Polymyxa betae

真菌多粘菌 Benyvirus (BNYVV) 的传播机制

基本信息

批准号：
18580042
负责人：
TAMADA Tetsuo
金额：
$ 2.41万
依托单位：
Okayama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18580042/
关键词：
Beet necrotic yellow vein virus Polymyxa betae Fungus transmission RNA silencing Beta vulgaris Virus resistance GFP-tagged virus テンサイ

项目摘要

Beet necrotic yellow vein virus (BNYVV, Benyvirus) causes rhizomania disease of sugar beet and is transmitted by Polymyxa betae. BNYVV has five RNA species (RNA1-5). RNA1 and RNA2 are involved in viral RNA replication, assembly, and cell-to-cell movement, and RNA3 to 5 are associated with vector-mediated infection and disease development in sugar beet roots. GFP-tagged BNYVV (BNYVV-GFP) was constructed by introducing the GFP gene into the coat protein readthrough domain of BNYVV RNA2. BNYVV-GFP was efficiently infectious to local lesion and systemic host plants and infection sites were followed up by expressing the green fluorescence. However, several GFP viruses constructed were not transmitted by P. betae so that we were not able to conduct transmission experiments using BNYVV-GFP. The vascular movement of BNYVV in beet plants was examined using BNYVV-GFP. The virus had difficulty to move from epidermal cells to phloem tissues when rub-inoculated into leaves. In roots, the vector-inoculated virus propagated in any tissues of rootlets, but it was difficult for virus to invade from rootlet tissues into phloem tissues of taproots and stems. Molecular analyses of RNA4-encoded p31 showed that BNYVV p31 plays a multifunctional role in efficient vector transmission, enhanced symptom expression and root-specific silencing suppression. The RNA3-encoded p25 protein is responsible for production of rhizomania symptoms. The presence of the p25 protein also was found to be associated with resistance response in resistant plants. There was a genotype-specific interaction between BNYVV strains and the beet plants. Three amino acid residues 68, 70, and 179 are important in determining the resistance phenotype, and that the host-genotype specificity is controlled by single amino acid changes at position 68. BNYVV resistance mechanisms in root and leaf may be different: the resistance appearing in leaves was stronger than that appearing in roots.

甜菜坏死性黄静脉病毒（BNYVV, Benyvirus）引起甜菜根瘤病，由甜菜多粘虫传播。BNYVV有5种RNA （RNA1-5）。RNA1和RNA2参与病毒RNA的复制、组装和细胞间运动，RNA3至rna5与甜菜根中媒介介导的感染和疾病发展有关。GFP标记的BNYVV （BNYVV-GFP）通过将GFP基因导入BNYVV RNA2的外壳蛋白读透结构域构建而成。BNYVV-GFP能有效感染局部病变和全身寄主植物，并通过表达绿色荧光对感染部位进行跟踪。然而，由于构建的几种GFP病毒不被P. betae传播，因此我们无法使用BNYVV-GFP进行传播实验。利用BNYVV- gfp检测了BNYVV在甜菜植株中的维管运动。当摩擦接种到叶片时，病毒很难从表皮细胞转移到韧皮部组织。在根中，载体接种的病毒可以在根的任何组织中繁殖，但病毒很难从根组织侵入主根和茎的韧皮部组织。rna4编码p31的分子分析表明，BNYVV p31在有效的载体传播、增强症状表达和根特异性沉默抑制中发挥多功能作用。rna3编码的p25蛋白负责产生根茎病症状。p25蛋白的存在也被发现与抗性植物的抗性反应有关。BNYVV菌株与甜菜植株之间存在基因型特异性相互作用。3个氨基酸残基68、70和179在确定抗性表型中起重要作用，宿主基因型特异性受68位单氨基酸变化控制。BNYVV在根和叶中的抗性机制可能不同，叶中的抗性强于根。