Hernández C, Mathis A, Brown D J, Bol J F
Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden, The Netherlands.
J Gen Virol. 1995 Nov;76 ( Pt 11):2847-51. doi: 10.1099/0022-1317-76-11-2847.
Tobacco rattle virus (TRV) isolate PPK20 is transmitted by Paratrichodorus pachydermus nematodes. The factor(s) determining vector transmissibility has been shown to be located on TRV RNA 2. Sequence determination revealed that PPK20 RNA 2 contains three open reading frames encoding the coat protein (cp) and proteins with molecular masses of 29.4 and 32.8 kDa. The 29.4 and 32.8 kDa protein-coding genes showed no significant sequence similarity to any other known tobravirus gene. A full-length cDNA of PPK20 RNA 2 cloned between the 35S promoter and nos terminator infected plants when co-inoculated with PPK20 RNA 1. Deletions in the reading frames of the 29.4 and 32.8 kDa proteins revealed that these sequences are dispensable for replication of PPK20 RNA 2 in plants. Subgenomic RNAs for translation of cp and the putative 29.4 and 32.8 kDa proteins were detected in infected leaves. The possible role of PPK20 RNA 2 non-structural genes in TRV vector transmission is discussed.
烟草脆裂病毒（TRV）分离株PPK20由厚皮拟毛刺线虫传播。已证明决定载体传播性的因子位于TRV RNA 2上。序列测定表明，PPK20 RNA 2包含三个开放阅读框，分别编码外壳蛋白（cp）以及分子量为29.4 kDa和32.8 kDa的蛋白质。29.4 kDa和32.8 kDa蛋白质编码基因与任何其他已知的烟草脆裂病毒基因均无明显序列相似性。当与PPK20 RNA 1共同接种时，克隆于35S启动子和nos终止子之间的PPK20 RNA 2全长cDNA可感染植物。29.4 kDa和32.8 kDa蛋白质阅读框中的缺失表明，这些序列对于PPK20 RNA 2在植物中的复制并非必需。在受感染叶片中检测到了用于cp以及假定的29.4 kDa和32.8 kDa蛋白质翻译的亚基因组RNA。本文讨论了PPK20 RNA 2非结构基因在TRV载体传播中的可能作用。
