黄瓜花叶病毒衣壳蛋白存在于被其侵染的烟草叶绿体中

用原生质体法制备出高纯度的完整叶绿体经SDS-PAGE电泳,银染后,发现黄瓜花叶病毒(CMV)侵染的烟草病叶叶绿体蛋白质图谱和健叶叶绿体相比,多出一条染色较弱的迁移率与CMV衣壳蛋白质相同的带,经Western转移,用CMV游离衣壳蛋白亚基抗血清进行斑点酶联(Immunoblot)检测,证明这条带就是CMV衣壳蛋白质。健康叶绿体中加入去掉叶绿体的病叶汁液而制备出的叶绿体中无CMV衣壳蛋白质,说明这不是在叶绿体提纯过程中得到的假象,即衣壳蛋白质存在于被CMV侵染的完整叶片叶绿体中。这个结果否认了以往报道的CMV衣壳蛋白质不存在于烟草叶绿体中的结论。另外还发现,叶绿体中的衣壳蛋白质浓度与叶片症状严重程度呈正相关。

Cucumber Mosaic Virus Coat Protein Inside the Chloroplast of the Infected Tobacco

The intact chloroplasts were made through protoplasts. In the SDSPAGE-silver stained gel, one extra protein band, which had the same mobility and molecular weight as the cucumber mosaic virus coat protein (CMV-cp), was found in the diseased chloroplast comparative to the health chloroplast. In the immunoblot testing, the band was highly reactive to the antiserum against the free CMV-cp, while the healthy and diseased sap treated healthy chloroplasts had no reaction. The result provides an evidence for the CMV-cp existence in the chloroplast. It was also found that the concentration of CMV-cp inside chloroplast was positively related to the severity of the symptom.