McGarvey P, Tousignant M, Geletka L, Cellini F, Kaper J M
Molecular Plant Pathology Laboratory, PSI, USDA, Beltsville, MD 20705, USA.
J Gen Virol. 1995 Sep;76 ( Pt 9):2257-70. doi: 10.1099/0022-1317-76-9-2257.
A cucumber mosaic virus (CMV-Ix) from Ixora is unusual in that it does not support the accumulation of some well-characterized CMV satellite RNAs in plants. CMV-Ix can support a particular satellite RNA variant which causes lethal tomato necrosis when inoculated with other CMV strains but not when inoculated with CMV-Ix. This difference in ability to support accumulation of specific satellite variants is apparent even when their sequences differ by only 10 nucleotides. Electroporation of tomato protoplasts with combinations of CMV-Ix or CMV-1 RNA plus the same satellite variants showed similar differences in accumulation, indicating a defect in satellite RNA replication and not movement or encapsidation. Pseudorecombinant virus infections between CMV-1 and CMV-Ix indicated that the genomic determinants responsible for this phenotype reside on RNA 1 since only combinations with CMV-Ix RNA 1 failed to replicate satellite RNA. The complete genome of CMV-Ix was cloned, sequenced and compared with the genomes of other cucumoviruses. CMV-Ix is most similar in RNA and protein sequence to subgroup 1 CMV-Fny and CMV-Y but slightly less similar than they are to each other. CMV-Ix and all cucumovirus strains sequenced thus far share a domain in the 3' untranslated portion of their genomic RNAs in which 39 of 40 bases are completely conserved.
一种来自龙船花属植物的黄瓜花叶病毒（CMV-Ix）不同寻常之处在于，它不能支持某些特性明确的黄瓜花叶病毒卫星RNA在植物中积累。CMV-Ix能支持一种特定的卫星RNA变体，该变体与其他黄瓜花叶病毒株系一起接种时会导致番茄致死性坏死，但与CMV-Ix一起接种时则不会。即使特定卫星变体的序列仅相差10个核苷酸，其在支持特定卫星变体积累能力上的这种差异也很明显。用CMV-Ix或CMV-1 RNA与相同卫星变体的组合对番茄原生质体进行电穿孔，结果显示在积累方面存在类似差异，这表明是卫星RNA复制存在缺陷，而非移动或衣壳化方面的缺陷。CMV-1和CMV-Ix之间的假重组病毒感染表明，负责这种表型的基因组决定因素位于RNA 1上，因为只有与CMV-Ix RNA 1的组合无法复制卫星RNA。CMV-Ix的完整基因组被克隆、测序，并与其他黄瓜花叶病毒的基因组进行了比较。CMV-Ix在RNA和蛋白质序列上与亚组1的CMV-Fny和CMV-Y最为相似，但相似度略低于它们彼此之间的相似度。CMV-Ix和迄今为止测序的所有黄瓜花叶病毒株系在其基因组RNA的3'非翻译区都有一个结构域，其中40个碱基中的39个是完全保守的。
