Biologisches Institut, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
Biologisches Institut, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
Virus Res. 2014 Apr;183:89-94. doi: 10.1016/j.virusres.2014.01.028. Epub 2014 Feb 14.
Long-term surviving sugar beet plants were investigated after beet curly top virus infection to characterize defective (D) viral DNAs as potential symptom attenuators. Twenty or 14 months after inoculation, 20 D-DNAs were cloned and sequenced. In contrast to known D-DNAs, they exhibited a large range of sizes. Deletions were present in most open reading frames except ORF C4, which encodes a pathogenicity factor. Direct repeats and inverted sequences were observed. Interestingly, the bidirectional terminator of transcription was retained in all D-DNAs. A model is presented to explain the deletion sites and sizes with reference to the viral minichromosome structure, and symptom attenuation by D-DNAs is discussed in relation to RNA interference.
长期存活的甜菜植物在感染甜菜曲顶病毒后被研究，以表征缺陷（D）病毒 DNA 作为潜在的症状减弱剂。接种后 20 或 14 个月，克隆并测序了 20 个 D-DNA。与已知的 D-DNA 相比，它们的大小范围很大。除了编码致病因子的 ORF C4 外，大多数开放阅读框都存在缺失。观察到直接重复和反向序列。有趣的是，所有 D-DNA 都保留了双向转录终止子。提出了一个模型，参考病毒微染色体结构，解释缺失位点和大小，并讨论 D-DNA 对 RNA 干扰的症状减弱作用。
