The State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
The Key Laboratory of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
Viruses. 2018 May 13;10(5):254. doi: 10.3390/v10050254.
is a necrotrophic fungus causing disease on many important agricultural crops. Two novel mycoviruses, namely Botrytis cinerea hypovirus 1 (BcHV1) and Botrytis cinerea fusarivirus 1 (BcFV1), were fully sequenced. The genome of BcHV1 is 10,214 nt long excluding a poly-A tail and possesses one large open reading frame (ORF) encoding a polyprotein possessing several conserved domains including RNA-dependent RNA polymerase (RdRp), showing homology to hypovirus-encoded polyproteins. Phylogenetic analysis indicated that BcHV1 may belong to the proposed genus Betahypovirus in the viral family . The genome of BcFV1 is 8411 nt in length excluding the poly A tail and theoretically processes two major ORFs, namely ORF1 and ORF2. The larger ORF1 encoded polypeptide contains protein domains of an RdRp and a viral helicase, whereas the function of smaller ORF2 remains unknown. The BcFV1 was phylogenetically clustered with other fusariviruses forming an independent branch, indicating BcFV1 was a member in Fusariviridae. Both BcHV1 and BcFV1 were capable of being transmitted horizontally through hyphal anastomosis. Infection by BcHV1 alone caused attenuated virulence without affecting mycelial growth, significantly inhibited infection cushion (IC) formation, and altered expression of several IC-formation-associated genes. However, wound inoculation could fully rescue the virulence phenotype of the BcHV1 infected isolate. These results indicate the BcHV1-associated hypovirulence is caused by the viral influence on IC-formation-associated pathways.
是一种引起许多重要农作物病害的坏死性真菌。两种新型真菌病毒，即 Botrytis cinerea hypovirus 1（BcHV1）和 Botrytis cinerea fusarivirus 1（BcFV1），已被完全测序。BcHV1 的基因组长 10214 个核苷酸，不包括 poly-A 尾巴，具有一个大的开放阅读框（ORF），编码一个具有几个保守结构域的多蛋白，包括 RNA 依赖性 RNA 聚合酶（RdRp），与 hypovirus 编码的多蛋白具有同源性。系统发育分析表明，BcHV1 可能属于病毒科中提出的 Beta hypovirus 属。BcFV1 的基因组长 8411 个核苷酸，不包括 poly-A 尾巴，理论上可加工两个主要的 ORF，即 ORF1 和 ORF2。较大的 ORF1 编码的多肽含有 RdRp 和病毒解旋酶的蛋白结构域，而较小的 ORF2 的功能尚不清楚。BcFV1 与其他 fusariviruses 聚集成一个独立的分支，与其他 fusariviruses 聚类在一起，表明 BcFV1 是 Fusariviridae 的一个成员。BcHV1 和 BcFV1 都能够通过菌丝吻合进行水平传播。单独感染 BcHV1 会导致毒力减弱而不影响菌丝生长，显著抑制感染垫（IC）的形成，并改变几个与 IC 形成相关的基因的表达。然而，伤口接种可以完全挽救感染 BcHV1 的分离物的毒力表型。这些结果表明，BcHV1 相关的弱毒力是由病毒对与 IC 形成相关的途径的影响引起的。
