State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China.
Virology. 2011 Sep 15;418(1):49-56. doi: 10.1016/j.virol.2011.07.008. Epub 2011 Aug 2.
Three dsRNA segments, two similarly sized at 9.5kbp and a third one of approximately 3.6kbp, were extracted from a hypovirulent strain SZ-150 of Sclerotinia sclerotiorum. The complete cDNA sequence of one of the two large dsRNA segment (10398bp, excluding the poly (A) tail) reveals a single ORF that encodes a polyprotein with conserved domains of putative papain-like protease, UDP glucose/sterol glycosyltransferase, RNA-dependent RNA polymerase and viral RNA Helicase. This virus is closely related to Cryphonectria hypovirus (CHV) 3/GH2 and CHV4/SR2 in the family Hypoviridae and designated as Sclerotinia sclerotiorum hypovirus 1 (SsHV1/SZ-150). The satellite-like 3.6kbp dsRNA segment (S-dsRNA) shares high sequence identity with the 5'-UTR of SsHV1/SZ-150. SsHV1/SZ-150 alone is not the primary causal agent for hypovirulence of strain SZ-150 since strains without the S-dsRNA show normal phenotype. This is the first report of a naturally occurring hypovirus that infects a fungus other than Cryphonectria parasitica.
从一个弱毒菌株 SZ-150 的核盘菌中提取了三个 dsRNA 片段，其中两个大小相似，约为 9.5kbp，第三个约为 3.6kbp。两个大 dsRNA 片段之一的完整 cDNA 序列（不包括 poly(A)尾）为 10398bp，揭示了一个单一的 ORF，该 ORF 编码一个具有假定的木瓜蛋白酶样蛋白酶、UDP 葡萄糖/固醇糖苷转移酶、RNA 依赖性 RNA 聚合酶和病毒 RNA 解旋酶保守结构域的多蛋白。该病毒与 Cryphonectria hypovirus (CHV) 3/GH2 和 CHV4/SR2 在 Hypoviridae 家族中密切相关，并被命名为 Sclerotinia sclerotiorum hypovirus 1 (SsHV1/SZ-150)。卫星样的 3.6kbp dsRNA 片段（S-dsRNA）与 SsHV1/SZ-150 的 5'-UTR 具有高度的序列同一性。单独的 SsHV1/SZ-150 并不是 SZ-150 菌株弱毒的主要原因，因为没有 S-dsRNA 的菌株表现出正常的表型。这是首例报道的感染非 Cryphonectria parasitica 的真菌的天然弱毒现象。
