College of Life Sciences, Henan Agricultural University, 95 Wenhua Road, Zhengzhou 450002, Henan, China.
Fungal Biol. 2010 May-Jun;114(5-6):507-13. doi: 10.1016/j.funbio.2010.04.001. Epub 2010 Apr 10.
Many cultivated mushroom strains, such as Pleurotus ostreatus TD300, displayed symptoms of degeneration. A spherical virus POSV and four dsRNA segments were extracted from mycelium of P. ostreatus TD300. POSV had a diameter of 23 nm and encapsidated a 2.5kb dsRNA segment with coat proteins whose molecular weights were 39 kDa and 30 kDa. Four dsRNA segments were 8.2 kb, 2.5 kb, 2.0 kb, and 1.1 kb in size, respectively. The 1.1 kb dsRNA segment often escaped detection. The cDNA and the amino acid sequences of the 8.2 kb dsRNA were homologous to those of RNA-dependent RNA polymerases (RDRP) of ssRNA oyster mushroom spherical virus (OMSV), and contained conserved motifs A to D which were almost identical to those in RDRP of OMSV. The cDNA and amino acid sequences of the 2.5 kb and 2.0 kb dsRNA segments were homologous to that of RDRP and capsid protein of dsRNA virus P. ostreatus virus 1 (PoV1), respectively. In particular, the amino acid sequence of 2.5 kb dsRNA segment had high identity with the conserved motifs A to C in RDRP of PoV1, a Partiviridae virus. After eliminating the viruses in P. ostreatus TD300, the symptoms of degeneration completely disappeared. The results reveal that P. ostreatus TD300 was at least infected by a particle virus POSV, and two naked viruses, one was a dsRNA virus with a 2.0 kb dsRNA segment, the other was an ssRNA virus whose replicating form of genome was an 8.2 kb dsRNA segment. Mycoviruses infection is a causative agent of mushroom strain degeneration.
许多栽培蘑菇菌株，如糙皮侧耳 TD300，表现出退化的症状。从糙皮侧耳 TD300 的菌丝体中提取了一种球形病毒 POSV 和四条 dsRNA 片段。POSV 的直径为 23nm，封装了一条 2.5kb 的 dsRNA 片段，外壳蛋白的分子量分别为 39kDa 和 30kDa。四条 dsRNA 片段分别为 8.2kb、2.5kb、2.0kb 和 1.1kb。1.1kb 的 dsRNA 片段经常检测不到。8.2kb dsRNA 的 cDNA 和氨基酸序列与 ssRNA 牡蛎蘑菇球形病毒（OMSV）的 RNA 依赖性 RNA 聚合酶（RDRP）同源，并包含保守基序 A 至 D，与 OMSV 的 RDRP 几乎相同。2.5kb 和 2.0kb dsRNA 片段的 cDNA 和氨基酸序列分别与 RDRP 和 dsRNA 病毒糙皮侧耳病毒 1（PoV1）的衣壳蛋白同源。特别是，2.5kb dsRNA 片段的氨基酸序列与 PoV1 的 RDRP 保守基序 A 至 C 高度同源，PoV1 是一种 Partiviridae 病毒。在消除糙皮侧耳 TD300 中的病毒后，退化的症状完全消失。结果表明，糙皮侧耳 TD300 至少感染了一种粒子病毒 POSV，以及两种裸露病毒，一种是带有 2.0kb dsRNA 片段的 dsRNA 病毒，另一种是 ssRNA 病毒，其基因组的复制形式是 8.2kb 的 dsRNA 片段。真菌病毒感染是蘑菇菌株退化的一个原因。
