瓜类褪绿黄化病毒外壳蛋白的亚细胞定位及致病作用浅析

瓜类褪绿黄化病毒(cucurbit chlorotic yellows virus, CCYV)是近些年来出现的一种烟粉虱 Bemisia tabaci传播的植物病毒,在瓜类生产中造成了严重损失。为了解该病毒外壳蛋白(coat protein, CP)在病毒侵染寄主过程中的亚细胞定位和致病作用,本研究以CCYV山东黄瓜分离物为研究对象,构建了荧光表达载体CP-YFP和异源表达载体pGR-CP。浸润荧光表达载体48 h后的本氏烟Nicotiana benthamiana叶片在激光共聚焦显微镜下可以观察到荧光信号在细胞质和细胞核内均有分布;浸润异源表达载体的本氏烟植株7 d后上部叶片开始显现花叶症状,13 d后顶部新叶出现严重皱缩和坏死斑点。以上结果表明CCYV CP蛋白参与了病毒对寄主的侵染过程,可能是症状形成的致病相关因子。本研究为进一步解析该病毒的致病机理提供了初步的理论支持。

Characterization of the subcellular localization and pathogenicity of cucurbit chlorotic yellows virus coat protein

Cucurbit chlorotic yellow virus (CCYV) is a kind of plant virus transmitted by whitefly. Recently, it has caused serious losses in the production of Cucurbitaceae crops. In order to study the subcellular localization and pathogenic characteristics of its coat protein (CP) during infection, the fluorescence vector CP-YFP and the heterologous expression vector pGR-CP were constructed based on CCYV Shandong isolate. After infiltrating the vector CP-YFP for 48 h, fluorescence signal could be observed in cytoplasm and nucleus of the Nicotiana benthamiana leaves under the laser confocal microscope. After seven days of infiltrating the vector pGR-CP, the upper leaves of N.benthamiana plants began to show mosaic symptoms, and 13 days later, the systemic leaves appeared severe chlorotic, crumple and necrotic spots. These results indicated that CP might be an important protein involved in the pathogenicity of CCYV. This study provided a preliminary theoretical support for further understanding the pathogenesis of this virus.