感染通天草（Uraria crinita）的花生條斑病毒（Peanut stripe virus）之鑑定

Identification of Peanut stripe virus infecting Uraria crinita

台灣栽培之藥材植物通天草發生疑似病毒病，從南投縣名間鄉採集具嵌紋病徵之通天草植株，經單斑分離得到一純系病毒株（9G-4）。經寄主範圍試驗、電子顯微鏡觀察、免疫電子顯微鏡觀察、電泳分析、西方轉漬反應及核酸與胺基酸序列比較，所分離的病毒株（9G-4）係花生條斑病毒（Peanut stripe virus，簡稱PStV）的一個系統（strain）。本病毒接種奎藜後產生局部壞疽病斑。病毒為長形顆粒狀，大小約790-810 × 12-14 nm。病毒接種至奎藜繁殖，再利用硫酸銫等密度平衡離心法純化，純化所得PStV試料用以注射白兔製備抗血清。電泳分析純化的病毒鞘蛋白，其主要蛋白分子量約為35 kDa。經西方轉漬反應、SDS-瓊脂免疫擴散反應（immunodiffusion），自製的抗體與PStV有同源（homologous）血清反應。從本病毒RNA 3'端解序1470個核苷酸，與GenBank中的PStV（Access No. AF132157）比較鞘蛋白基因之核苷酸的相同度達88.8％，而其胺基酸相似度則為87.8％。本報告為PStV感染通天草的首篇紀錄。

"Uraria crinita (L.) Desv. Ex DC. a kind of medicinal plant cultivated in Taiwan was found to be infected by virus. A plant with leaf mosaic was collected from Nantou and from which a pure line of virus isolate (9G-4) was obtained through series of single lesion isolation. By host range test, electron microscope observation, immunosorbent electron microscopy, Ouchterlony immunodiffusion, coat protein electrophoresis, Western blotting, and RNA sequencing, the virus was identified as a strain of Peanut stripe virus (PStV). The virus systemically infected Uraria crinita and caused mosaic symptom, but locally infected Chenopodium amaranticolor, C. quinoa caused necrotic lesions. Electron microscopy of diseased tissue showed filamentous virus particles with 790-810 × 12-14 nm. The virus was purified from inoculated leaves of C. quinoa by isopycnic centrifugation in cesium sulfate and the purified preparation was used to inject rabbit for antiserum production. In SDS-PAGE, the virus was found consisting of one species of coat protein subunit and its molecular weight was estimated to be 35 kDa. In SDS-immunodiffusion, Ouchterlony method and Western blot, the prepared antiserum homologouslly reacted with PStV antigen. Total of 1470 nucleotides from the 3'-end region of this virus were sequenced and compared with those of Peanut stripe virus listed in GenBank (Access No. AF132157). The nucleotide identity of this CP is 88.8% and the amino acid similarity is 87.8%. This is the first report of Peanut stripe virus infecting Uraria crinita in Taiwan."