A double-stranded RNA (dsRNA) mycovirus from the phytopathogenic fungus Alternaria alternata, which causes watermelon leaf blight, was characterized. The genome of this virus has eight dsRNA segments, ranging from 1039 bp to 2398 bp. DsRNAs 1-6 each contain a single large open reading frame (ORF), while dsRNAs 7 and 8 each dsRNA contain two ORFs. The RNA-dependent RNA polymerase (RdRp) encoded by dsRNA1 and the viral methyltransferase encoded by dsRNA3 share 97.6% and 98.9% amino acid sequence identity, respectively, with the corresponding proteins of Plasmopara viticola lesion associated polymycovirus 1. The dsRNA5-encoded proline-alanine-serine-rich protein shows 48.1% sequence identity to that of Beauveria bassiana polymycovirus 3. The proteins encoded on dsRNAs 2, 4, and 8 have 99.7%, 98.2%, and 65.1% sequence identity, respectively, to the corresponding proteins of a mycovirus identified in Alternaria sp. FA0703 (AltR1). The proteins encoded by dsRNAs 6 and 7 do not match any known proteins of mycoviruses. Phylogenetic analysis of the RdRp domain showed that the virus clustered with members of the family Polymycoviridae. Based on these characteristics, the mycovirus was identified as a polymycovirus and designated as "Alternaria alternata polymycovirus 1" (AaPmV1). This is the first report of a polymycovirus associated with A. alternata.

中文翻译：

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导致西瓜叶枯病的链格孢中一种新型多霉菌病毒的鉴定和基因组特征。

鉴定了一种来自植物病原真菌交链格孢菌的双链 RNA (dsRNA) 真菌病毒，它会导致西瓜叶枯病。该病毒的基因组有 8 个 dsRNA 片段，范围从 1039 bp 到 2398 bp。DsRNA 1-6 每个都包含一个大的开放阅读框 (ORF)，而 dsRNA 7 和 8 每个 dsRNA 都包含两个 ORF。由 dsRNA1 编码的 RNA 依赖性 RNA 聚合酶 (RdRp) 和由 dsRNA3 编码的病毒甲基转移酶分别具有 97.6% 和 98.9% 的氨基酸序列同一性，与葡萄球菌病变相关多霉菌病毒 1 的相应蛋白质。dsRNA5 编码的脯氨酸-富含丙氨酸丝氨酸的蛋白质与白僵菌多霉菌病毒 3 的序列同一性为 48.1%。dsRNA 2、4 和 8 上编码的蛋白质分别具有 99.7%、98.2% 和 65.1% 的序列同一性，与链格孢菌中鉴定的真菌病毒的相应蛋白质。FA0703 (AltR1)。dsRNAs 6 和 7 编码的蛋白质与任何已知的真菌病毒蛋白质都不匹配。RdRp 结构域的系统发育分析表明该病毒与多霉菌病毒科的成员聚集在一起。基于这些特征，该真菌病毒被鉴定为多真菌病毒并命名为“Alternaria alternata polymycovirus 1”(AaPmV1)。这是与 A. alternata 相关的多霉菌病毒的第一份报告。该真菌病毒被鉴定为多真菌病毒并命名为“Alternaria alternata polymycovirus 1”(AaPmV1)。这是与 A. alternata 相关的多霉菌病毒的第一份报告。该真菌病毒被鉴定为多真菌病毒并命名为“Alternaria alternata polymycovirus 1”(AaPmV1)。这是与 A. alternata 相关的多霉菌病毒的第一份报告。