The occurrence of CMV-specific short RNAs in transgenic tobacco expressing virus-derived double-stranded RNA is indicative of resistance to the virus
The occurrence of CMV-specific short RNAs in transgenic tobacco expressing virus-derived double-stranded RNA is indicative of resistance to the virus
复制标题
DOI：
10.1094/mpmi.2002.15.8.826
复制
发表时间：
2002-08-01
影响因子：
3.5
通讯作者：
Tsagris, M
中科院分区：
文献类型：
--
作者：
Kalantidis, K;Psaradakis, S;Tsagris, M
在真核细胞中表达或引入双链RNA可以触发转基因、内源基因和病毒的序列特异性基因沉默。产生与病毒序列同源的dsrna的转基因植物可能对病毒表现出病原体来源的抗性。黄瓜花叶病毒（CMV）是一种非常广泛的病毒，有超过1000种宿主，具有抑制沉默以建立感染的天然能力。在这里，我们报道了转基因烟草系的产生，其中含有CMV cDNA的倒置重复的DNA转基因已经被引入。这种DNA结构的表达传递了能够形成分子内双链的RNA转录本。转基因植物被CMV侵染，可分为三类植物：易感植物，其反应症状通常比野生型对照轻；“恢复”表型，其中新出现的叶子没有症状；以及表现出完全抗性的植物。Northern分析表明，CMV dsRNA的表达在一些转基因品系中引起了具有转录后基因沉默特征的短rna的产生。这些品系是抗巨细胞病毒的。短rna检测与病毒抗性之间的相关性提供了一种分子标记，使预测通过dsRNA设计病毒抗性的尝试成功成为可能。
Expression or introduction of double-stranded (ds)RNA in eukaryotic cells can trigger sequence-specific gene silencing of transgenes, endogenes, and viruses. Transgenic plants producing dsRNAs with homology to viral sequences are likely to exhibit pathogen-derived resistance to the virus. Cucumber mosaic virus (CMV), a very widespread virus with over 1,000 host species, has the natural ability to suppress silencing in order to establish infection. Here, we report the generation of transgenic tobacco lines, where a DNA transgene containing an inverted repeat of CMV cDNA had been introduced. Expression of this DNA construct delivered an RNA transcript that is able to form an intramolecular double strand. Transgenic plants were challenged with CMV Three categories of plants could be discriminated: susceptible plants, which typically reacted with milder symptoms than the wild-type control; a "recovery" phenotype, in which newly emerging leaves were free of symptoms; and plants that showed complete resistance. Northern analysis showed that the expression of CMV dsRNA caused, in some transgenic lines, the generation of short RNAs characteristic of posttranscriptional gene silencing. Those lines were CMV resistant. The correlation between the detection of short RNAs and virus resistance provides a molecular marker that makes it possible to predict success in attempts to engineer virus resistance by dsRNA.