Rong Rui, Rao Shujing, Scott Simon W, Carner Gerald R, Tainter Frank H
Department of Forest Resources, Clemson University, Clemson, SC 29634, USA.
Virus Res. 2002 Dec;90(1-2):217-24. doi: 10.1016/s0168-1702(02)00178-8.
Complete nucleotide sequences were determined for the four dsRNA segments present in isolate 247 of Discula destructiva from South Carolina. The largest dsRNA (dsRNA 1) was 1787 bp in length with a single open reading frame (ORF) that coded for a putative RNA-dependent RNA polymerase (RdRp). The dsRNA 2 was 1585 bp in length with a single ORF that coded for a putative viral coat protein. Both the dsRNA 3 (1178 bp in length) and dsRNA 4 (308 bp) contained single ORFs. However, neither the nucleotide sequence nor the sequence of the putative translation products, showed any similarity with sequences currently available from GenBank. Although distinct, all 4 dsRNAs showed conserved nucleotides at both the 5' and 3' termini. Sequences of the two dsRNAs in an isolate of D. destructiva (331 originating from Idaho) were similar in length to, and shared similarity with, the dsRNA 1 and dsRNA 2 of isolate 247. However, although the putative RdRps of isolates 247 and 331 are closely related, the putative viral coat proteins coded for by the respective dsRNA 2s are distinct. Thus, the dsRNAs in the two fungal isolates appeared to originate from distinct, but related viruses, which we have named D. destructiva virus 1 and D. destructiva virus 2, respectively. Phylogenetic analysis indicated that the two viruses were most closely related to Fusarium solani virus 1 and should be considered members of the genus Partitivirus. Another isolate of D. destructiva (272.1) contains a 12 kb dsRNA in addition to the 4 dsRNAs found in isolate 247. Partial sequence of this 12 kb molecule showed a relationship to other large dsRNA molecules isolated from plants.
测定了来自南卡罗来纳州的毁灭盘多毛孢菌（Discula destructiva）分离株247中存在的4个双链RNA片段的完整核苷酸序列。最大的双链RNA（双链RNA1）长度为1787 bp，具有一个单一的开放阅读框（ORF），编码一种假定的RNA依赖RNA聚合酶（RdRp）。双链RNA2长度为1585 bp，具有一个单一的ORF，编码一种假定的病毒外壳蛋白。双链RNA3（长度为1178 bp）和双链RNA4（308 bp）都包含单一的ORF。然而，核苷酸序列及其假定翻译产物的序列与GenBank中目前可用的序列均无任何相似性。尽管不同，但所有4个双链RNA在5'和3'末端都显示出保守的核苷酸。毁灭盘多毛孢菌分离株（源自爱达荷州的331）中的两个双链RNA的序列长度与分离株247的双链RNA1和双链RNA2相似，并与它们有相似性。然而，尽管分离株247和331的假定RdRp密切相关，但各自双链RNA2编码的假定病毒外壳蛋白是不同的。因此，这两个真菌分离株中的双链RNA似乎源自不同但相关的病毒，我们分别将其命名为毁灭盘多毛孢菌病毒1和毁灭盘多毛孢菌病毒2。系统发育分析表明，这两种病毒与茄腐镰刀菌病毒1关系最为密切，应被视为分体病毒属的成员。毁灭盘多毛孢菌的另一个分离株（272.1）除了含有分离株247中发现的4个双链RNA外，还含有一个12 kb的双链RNA。这个12 kb分子的部分序列显示出与从植物中分离的其他大双链RNA分子的关系。
