Hellwald K H, Palukaitis P
Department of Plant Pathology, Cornell University, Ithaca, New York 14853.
J Gen Virol. 1994 Aug;75 ( Pt 8):2121-5. doi: 10.1099/0022-1317-75-8-2121.
Replicase-mediated resistance represents a genetically engineered form of resistance against viral infections and is established by using an intact or modified viral polymerase (replicase) gene for the transformation of the host. The K strain of cucumber mosaic cucumovirus (K-CMV) has been shown to break replicase-mediated resistance generated using a modified RNA2 of the subgroup I strain Fny-CMV. A full-length cDNA clone of K-CMV RNA2 was generated and RNA transcripts were shown to be infectious in combination with Fny-CMV RNAs 1 and 3. We further demonstrate that the ability of K-CMV to overcome resistance in the transgenic plants maps to RNA2. The complete nucleotide sequence of this RNA was determined and sequence differences from Fny-CMV RNA2 are discussed with regard to functional domains and their possible involvement in resistance breakage.
复制酶介导的抗性代表了一种针对病毒感染的基因工程抗性形式，它是通过使用完整的或修饰的病毒聚合酶（复制酶）基因转化宿主而建立的。黄瓜花叶黄瓜病毒（K-CMV）的K株已被证明能打破利用I亚组Fny-CMV株系修饰的RNA2产生的复制酶介导的抗性。构建了K-CMV RNA2的全长cDNA克隆，并证明RNA转录本与Fny-CMV RNA1和RNA3组合时具有感染性。我们进一步证明，K-CMV克服转基因植物中抗性的能力定位于RNA2。测定了该RNA的完整核苷酸序列，并讨论了与Fny-CMV RNA2在功能域方面的序列差异及其可能与抗性突破的关系。
