黄瓜花叶病毒番茄蕨叶分离物外壳蛋白基因的克隆和序列分析

Cloning and Sequencing of Cucumber Mosaic Virus Coat Protein Gene from Tomato

在北京延庆的番茄上分离到1株黄瓜花叶病毒(Cucumber mosaic virus,CMV)分离物CMV-YQ,该分离物在番茄上造成严重的蕨叶、矮化,在烟草上表现花叶、矮化和畸形,表现出很强的致病性。根据黄瓜花叶病毒外壳蛋白(coat protein,CP)基因的保守序列设计引物,利用RT-PCR技术对其CP基因片段进行了扩增并克隆,获得了含该基因全长657 bp的cDNA片段。序列测定与比较分析结果表明,北京地区造成番茄蕨叶的CMV分离物CP基因片段核酸序列与GenBank上CMV亚组Ⅰ其他分离物同源性高达90%～99%,属于CMV亚组Ⅰ。该分离物与分离于我国芭蕉的另一亚组Ⅰ分离物GB同源性为94.37%,两分离物之间存在寄主适应性变异。

A Cucumber mosaic virus（CMV） isolated from tomato which was grown in Yanqing County of Beijing was obtained. It induced severe symptoms of dwarf and linear leaf in tomato plants and mosaic, deformation and dwarf in tobacco. Primers were designed according to the conservative sequences of coat protein genes of CMVs and RT-PCR was used to clone the coat protein gene. Sequence analysis revealed that the coat protein gene comprised of 657 nucleotides encoding a protein of 218 amino acids and shared 90% - 99% sequence homology with CMV subgroup Ⅰ strains from GenBank,belonging to CMV subgroup Ⅰ . It shared 94.37% sequence homology with a subgroup Ⅰ isolate CMV-GB from Chinese banana and showed somewhat differentiation.