Lartey R T, Lane L C, Melcher U
Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater.
Arch Virol. 1994;138(3-4):287-98. doi: 10.1007/BF01379132.
We recently isolated turnip vein-clearing virus (TVCV), a tobamovirus which causes vein clearing in Brassica rapa (turnip) and a mosaic in Nicotiana tabacum (tobacco). We present an electron microscopic and molecular characterization of TVCV. Viral particles from lower epidermis peel contained rod-shaped viral particles, typical of tobamoviruses. Viral RNA extracted from infected turnip leaves was used as template for cDNA synthesis prior to cloning in a plasmid vector. Inserts of selected cDNA clones were sequenced to obtain the nucleotide sequence of the 126 K replicase component. The nucleotide and predicted amino acid sequences were 56 to 59% identical to those of most other sequenced tobamoviruses. The least related sequence, that of cucumber green mottle mosaic virus, was more related to the TVCV lineage than it was to those of the other sequenced tobamoviruses. UV spectroscopy suggested a tryptophan content characteristic of the ribgrass mosaic virus (RMV) group. Fragmentation of the TVCV coat protein by cyanogen bromide treatment produced a profile of fragments indistinguishable from those generated from the coat protein of RMV. Thus, while symptoms of TVCV infection on Nicotiana tabacum cv. Samsun and Nicotiana clevelandii differ from those reported for RMV, TVCV appears to be closely related to RMV.
我们最近分离出芜菁脉明病毒（TVCV），这是一种烟草花叶病毒属病毒，可导致芜菁（Brassica rapa）出现脉明症状，并在烟草（Nicotiana tabacum）上引发花叶病。我们展示了TVCV的电子显微镜和分子特征。从下表皮剥离物中提取的病毒粒子含有杆状病毒粒子，这是烟草花叶病毒属病毒的典型特征。从受感染的芜菁叶片中提取的病毒RNA在克隆到质粒载体之前用作cDNA合成的模板。对选定的cDNA克隆的插入片段进行测序，以获得126K复制酶组分的核苷酸序列。该核苷酸和预测的氨基酸序列与大多数其他已测序的烟草花叶病毒属病毒的序列具有56%至59%的同一性。相关性最低的序列，即黄瓜绿斑驳花叶病毒的序列，与TVCV谱系的相关性高于与其他已测序的烟草花叶病毒属病毒的相关性。紫外光谱分析表明其色氨酸含量具有车前草花叶病毒（RMV）组的特征。用溴化氰处理TVCV衣壳蛋白产生的片段图谱与RMV衣壳蛋白产生的片段图谱无法区分。因此，虽然TVCV感染烟草品种Samsun和克利夫兰烟草的症状与报道的RMV症状不同，但TVCV似乎与RMV密切相关。
