Acta Virol. 2022;66(3):206-215. doi: 10.4149/av_2022_302.
The genome sequence of a closterovirus (genus Closterovirus, family Closteroviridae), tentatively named Thesium chinense closterovirus 1 (TcCV1), was identified by performing high-throughput RNA-sequencing of the haustoria and root tissues of Thesium chinense, a parasitic plant. The TcCV1 genome was predicted to encode nine proteins, eight of which have orthologs in previously identified closteroviruses. The TcCV1 RNA-dependent RNA polymerase (RdRp) and heat shock protein 70 homolog (Hsp70h) showed 27.8-68.2% and 23.8-55.1% amino acid identity, respectively, to orthologous proteins of known closteroviruses. The putative +1 ribosomal frameshifting site required for producing RdRp was identified as GUUUAGC with UAG stop codon and the skipped nucleotide U. Phylogenetic trees based on RdRp and Hsp70h show that TcCV1 is a novel member of the genus Closterovirus, forming a subclade with a group of known closteroviruses, including mint virus 1 and carnation necrotic fleck virus. The genome sequence of TcCV1 may be useful for studying the genome evolution of closteroviruses. Keywords: Thesium chinense closterovirus 1; Closterovirus; Closteroviridae; Thesium chinense.
一株列当寄生植物中华列当（Thesium chinense）吸器和根组织的高通量 RNA 测序中，鉴定出一种暂定名为中华列当番茄潜隐病毒 1（TcCV1）的裂殖病毒（Closterovirus）（属裂殖病毒科 Closteroviridae）的基因组序列。预测 TcCV1 基因组编码 9 种蛋白，其中 8 种在先前鉴定的裂殖病毒中有同源物。TcCV1 的 RNA 依赖性 RNA 聚合酶（RdRp）和热休克蛋白 70 同源物（Hsp70h）与已知裂殖病毒的同源蛋白的氨基酸同一性分别为 27.8-68.2%和 23.8-55.1%。产生 RdRp 所需的推定+1 核糖体移码位点被鉴定为 GUUUAGC，带有 UAG 终止密码子和跳过的核苷酸 U。基于 RdRp 和 Hsp70h 的系统发育树表明，TcCV1 是裂殖病毒属的一个新成员，与一组已知的裂殖病毒形成一个亚群，包括薄荷病毒 1 和康乃馨坏死斑病毒。TcCV1 的基因组序列可能有助于研究裂殖病毒的基因组进化。关键词：中华列当番茄潜隐病毒 1；裂殖病毒；裂殖病毒科；中华列当。
