烟草脉扭病毒基因组部分序列的克隆和分析

Cloning and Analysis of Partial Genome Sequence of Tobacco vein distorting virus

烟草脉扭病毒(Tobacco vein distorting virus, TVDV)是引起烟草丛顶病的两种病毒之一。TVDV被归为黄症病毒科的暂定成员。应用黄症病毒科的通用引物和根据马铃薯卷叶病毒属成员核酸序列设计的简并引物,通过RT—PCR从烟草丛顶病烟株总RNA中扩增到了TVDV基因组的部分序列。序列分析获得了长度为1654 bp的序列,编码推测的TVDV复制酶基因的部分序列、外壳蛋白基因及运动蛋白基因的全部序列。根据这三个基因编码的氨基酸序列构建的分子进化树分析表明,TVDV为黄症病毒科的确定成员。根据其基因间隔区的长度特征和各ORF编码的氨基酸的分子进化分析,我们推测TVDV应当是马铃薯卷叶病毒属的一个新成员。这是TVDV的分子生物学特征的首次报道。

Tobacco vein distorting virus ( TVDV ) is one of the casual agents of tobacco bushy top disease. It was designated a tentative member of the family Luteoviridae. Partial sequence of the genome of TVDV was amplified by RT-PCR from total RNA of tobacco affected with tobacco bushy top disease,using universal primers of Luteoviruses and degenerate primer of Poleroviruses. The 1654 bp sequence of TVDV genome encoded partial putative RNA-dependent RNA polymerase, coat protein and movement protein. Molecular phylogenetic trees were constructed based on the amino acid sequence of these three proteins, indicating that TVDV should be a definitive member of the family Luteoviridae. According to the higher identities of amino acids of ORFs and the similar length of intergenic spacer region of TVDV with the member of the genus Polerovirus, we proposed that TVDV was a new member in the genus Polerovirus. This is the first report on the molecular properties of TVDV.