Molecular characterization of a novel hypovirus from the plant pathogenic fungus Fusarium graminearum
Molecular characterization of a novel hypovirus from the plant pathogenic fungus Fusarium graminearum
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植物病原真菌禾谷镰刀菌新型低病毒的分子特征
DOI：
10.1016/j.virol.2015.02.047
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发表时间：
2015-07-01
期刊：
影响因子：
3.7
通讯作者：
Guo, Lihua
中科院分区：
文献类型：
--
作者：
Li, Pengfei;Zhang, Hailong;Guo, Lihua
从禾谷镰刀菌（Fusarium graminearum）JS 16菌株中分离到一种新的真菌病毒，命名为禾谷镰刀菌低病毒2（Fusarium graminearum Hypovirus 2，FgHV 2/JS 16）。FgHV 2/JS 16的基因组是12，800个核苷酸（nts）长，不包括聚（A）尾。该基因组只有一个大的开放阅读框架，编码一个多聚蛋白，包含木瓜蛋白酶样蛋白酶、RNA依赖性RNA聚合酶、RNA解旋酶三个正常功能结构域和一个新的具有同源细菌SMC（染色体结构维持）染色体分离蛋白的结构域。在菌株JS 16中还检测到一个长度为4553-nt的缺陷RNA片段，不包括poly（A）尾。与栗疫病菌低病毒1型（CHV 1）和CHV 2的氨基酸同源性分别为16.8%和16.2%。基于多蛋白的多重比对的系统发育分析清楚地将贫病毒科的成员分为两个主要组，表明FgHV 2/JS 16是新提出的α-贫病毒属的一种新的贫病毒，由第1组的成员组成，包括CHV 1，CHV 2，FgHV 1和核盘菌贫病毒2。通过比较FgHV 2/JS 16感染和不感染FgHV 2/JS 16的等基因株的生物学特性，发现FgHV 2/JS 16与弱毒力表型相关。此外，我们还通过相对定量的真实的RT-PCR证实了FgHV 2/JS 16感染激活了禾谷镰刀菌的RNA干扰途径。(C)2015 Elsevier Inc. All rights reserved.
A novel mycovirus, termed Fusarium graminearum Hypovirus 2 (FgHV2/JS16), isolated from a plant pathogenic fungus, Fusarium graminearum strain JS16, was molecularly and biologically characterized. The genome of FgHV2/JS16 is 12,800 nucleotides (nts) long, excluding the poly (A) tail. This genome has only one large putative open reading frame, which encodes a polyprotein containing three normal functional domains, papain-like protease, RNA-dependent RNA polymerase, RNA helicase, and a novel domain with homologous bacterial SMC (structural maintenance of chromosomes) chromosome segregation proteins. A defective RNA segment that is 4553-nts long, excluding the poly (A) tail, was also detected in strain JS16. The polyprotein shared significant aa identities with Cryphonectria hypovirus 1 (CHV1) (16.8%) and CHV2 (16.2%). Phylogenetic analyses based on multiple alignments of the polyprotein clearly divided the members of Hypoviridae into two major groups, suggesting that FgHV2/JS16 was a novel hypovirus of a newly proposed genus-Alphahypovirus-composed of the members of Group 1, including CHV1, CHV2, FgHV1 and Sclerotinia sclerotiorum hypovirus 2. FgHV2/JS16 was shown to be associated with hypovirulence phenotypes according to comparisons of the biological properties shared between FgHV2/JS16-infected and FgHV2/JS16-free isogenic strains. Furthermore, we demonstrated that FgHV2/JS16 infection activated the RNA interference pathway in Fusarium graminearum by relative quantitative real time RT-PCR. (C) 2015 Elsevier Inc. All rights reserved.