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Abstract：
The phylogenetic relationships of ninety-five rose rosette virus (RRV) isolates with full-length genomic sequences were analyzed. These isolates were recovered mostly from commercial roses that are vegetatively propagated rather than grown from seed. First, the genome segments were concatenated, and the maximum likelihood (ML) tree shows that the branches arrange independent of their geographic origination. There were six major groups of isolates, with 54 isolates in group 6 and distributed in two subgroups. An analysis of nucleotide diversity across the concatenated isolates showed lower genetic differences among RNAs encoding the core proteins required for encapsidation than the latter genome segments. Recombination breakpoints were identified near the junctions of several genome segments, suggesting that the genetic exchange of segments contributes to differences among isolates. The ML analysis of individual RNA segments revealed different relationship patterns among isolates, which supports the notion of genome reassortment. We tracked the branch positions of two newly sequenced isolates to highlight how genome segments relate to segments of other isolates. RNA6 has an interesting pattern of single-nucleotide mutations that appear to influence amino acid changes in the protein products derived from ORF6a and ORF6b. The P6a proteins were typically 61 residues, although three isolates encoded P6a proteins truncated to 29 residues, and four proteins extended 76-94 residues. Homologous P5 and P7 proteins appear to be evolving independently. These results suggest greater diversity among RRV isolates than previously recognized.
摘要：
分析了95个具有全长基因组序列的玫瑰玫瑰花结病毒（RRV）分离株的系统发育关系。这些分离株主要是从无性繁殖的商业玫瑰中回收的，而不是从种子中生长出来的。首先,基因组片段连接在一起，并且最大似然（ML）树表明分支的排列与它们的地理起源无关。有六组主要的分离株，第6组中有54个分离株，分布在两个亚组中。对连接的分离株的核苷酸多样性的分析表明，与后者的基因组片段相比，编码衣壳化所需的核心蛋白的RNA之间的遗传差异较低。在几个基因组片段的连接处附近发现了重组断点，这表明片段的遗传交换有助于分离株之间的差异。对单个RNA片段的ML分析揭示了分离株之间不同的关系模式，这支持了基因组重组的概念。我们追踪了两个新测序的分离株的分支位置，以突出基因组片段如何与其他分离株的片段相关。RNA6具有有趣的单核苷酸突变模式，似乎会影响衍生自ORF6a和ORF6b的蛋白质产物中的氨基酸变化。P6a蛋白通常为61个残基，尽管三个分离株编码截短至29个残基的P6a蛋白，和四个蛋白质延伸76-94个残基。同源P5和P7蛋白似乎独立进化。这些结果表明，RRV分离株之间的多样性比以前认识到的要大。
