Trichoderma atroviride is a common fungus found in various ecosystems that shows mycoparasitic ability on other fungi. A novel dsRNA virus was isolated from T. atroviride NFCF377 strain and its molecular features were analyzed. The viral genome consists of a single segmented double-stranded RNA and is 9,584 bp in length, with two discontinuous open reading frames (ORF1 and ORF2). A mycoviral structural protein and an RNA-dependent RNA polymerase (RdRp) are encoded by ORF1 and ORF2, respectively, between which is found a canonical shifty heptameric signal motif (AAAAAAC) followed by an RNA pseudoknot. Analysis of sequence similarity and phylogeny showed that it is closely related to members of the proposed family “Fusagraviridae”, with a highest similarity to the Trichoderma atroviride mycovirus 1 (TaMV1). Although the sequence similarity of deduced amino acid to TaMV1 was evident, sequence deviations were distinctive at untranslated regions (UTRs) due to the extended size. Thus, we inferred this dsRNA to be a different strain of Trichoderma atroviride mycovirus 1 (TaMV1-NFCF377). Electron microscopy image exhibited an icosahedral viral particle of 40 nm diameter. Virus-cured isogenic isolates were generated and no differences in growth rate, colony morphology, or conidia production were observed between virus-infected and virus-cured strains. However, culture filtrates of TaMV1-NFCF377-infected strain showed enhanced antifungal activity against the plant pathogen Rhizoctonia solani but not to edible mushroom Pleurotus ostreatus. These results suggested that TaMV1-NFCF377 affected the metabolism of the fungal host to potentiate antifungal compounds against a plant pahogen, but this enhanced antifungal activity appeared to be species-specific.

木霉阿特罗韦德是一种在各种生态系统中发现的常见真菌，对其他真菌表现出霉菌寄生能力。一种新颖的dsRNA病毒从T.分离深绿NFCF377应变和其分子的功能进行了分析。病毒基因组由一个单段双链RNA组成，长9,584 bp，带有两个不连续的开放阅读框（ORF1和ORF2）。霉菌病毒结构蛋白和RNA依赖性RNA聚合酶（RdRp）分别由ORF1和ORF2编码，在二者之间发现了典型的移位七聚体信号基序（AAAAAAC），其后是RNA假结。对序列相似性和系统发育的分析表明，它与拟议家族“ Fusagraviridae”的成员密切相关，与阿奇木霉的相似性最高分枝杆菌病毒1（TaMV1）。尽管推导的氨基酸与TaMV1的序列相似性是显而易见的，但由于扩展的大小，在非翻译区（UTR）的序列偏差非常明显。因此，我们推断此dsRNA是木霉阿特罗韦德霉菌分枝病毒1（TaMV1-NFCF377）的不同菌株。电子显微镜图像显示直径为40 nm的二十面体病毒颗粒。产生了病毒治疗的同基因分离株，在病毒感染和病毒治疗的菌株之间未观察到生长速率，菌落形态或分生孢子产生的差异。但是，感染了TaMV1-NFCF377的菌株的培养滤液显示出对植物病原体solani Rhizoctonia solani的增强的抗真菌活性，但对可食用的平菇菇没有。 这些结果表明，TaMV1-NFCF377影响真菌宿主的代谢，以增强针对植物致热原的抗真菌化合物，但这种增强的抗真菌活性似乎是物种特异性的。