Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, Hunan Agricultural University, Nongda Road 1, Furong District, Changsha 410128, China.
Viruses. 2019 Mar 5;11(3):223. doi: 10.3390/v11030223.
Here, the molecular characterization of a novel mycovirus that was isolated from a phytopathogenic fungus and designed as ourmia-like virus 4 (MOLV4) is reported. MOLV4 has a genome that is 2497 bp long and possesses a single open reading frame (ORF), which encodes the product RNA-dependent RNA polymerase (RdRp). Sequence similarities were found between the MOLV4 encoded RdRp and the counterparts of a few previously reported ourmia-like mycoviruses. Virus-curing and biological comparison indicate that the virus has no or mild effects on the morphology and mycelium growth rate of the host fungus. Phylogenetic analysis using the RdRp aa sequences was performed. The results show that MOLV4 is clustered with the ourmia-like mycoviruses, forming a clade closely related to ourmiaviruses but distinct from narnaviruses. In addition, database searches revealed that several MOLV4-related sequences are present in the transcriptome shotgun assembly (TSA) library, expressed sequence tag database (ESTdb), whole-genome shotgun (WGS) library, and genomic survey sequences (GSS) libraries of a few other species of eukaryote organisms. Our results show that MOLV4, together with other similar ourmia-like mycoviruses, might represent a virus clade that links the plant ourmiaviruses and fungal narnaviruses and has a wide range of hosts.
本文报道了一种从植物病原真菌中分离得到的新型真菌病毒的分子特征，并将其命名为“奥密利亚样病毒 4（MOLV4）”。MOLV4 的基因组全长 2497 个核苷酸，含有一个开放阅读框（ORF），编码 RNA 依赖的 RNA 聚合酶（RdRp）。MOLV4 编码的 RdRp 与一些已报道的奥密利亚样真菌病毒的 RdRp 具有序列相似性。病毒祛除和生物学比较表明，该病毒对宿主真菌的形态和菌丝生长速度没有或只有轻微的影响。利用 RdRp 氨基酸序列进行系统发育分析。结果表明，MOLV4 与奥密利亚样真菌病毒聚类在一起，形成一个与奥密利亚病毒密切相关但与纳拉病毒不同的分支。此外，数据库搜索显示，几个 MOLV4 相关序列存在于几个真核生物的转录组鸟枪法组装（TSA）文库、表达序列标签数据库（ESTdb）、全基因组鸟枪法（WGS）文库和基因组调查序列（GSS）文库中。我们的研究结果表明，MOLV4 与其他类似的奥密利亚样真菌病毒一起，可能代表一个病毒分支，连接了植物奥密利亚病毒和真菌纳拉病毒，并具有广泛的宿主范围。
