A novel mycovirus named Fusarium oxysporum f. sp. dianthi hypovirus 2 (FodHV2) has been identified infecting isolates Fod 408 and Fod 409 of Fusarium oxysporum f. sp. dianthi from Morocco. The genome of FodHV2 is 9,444 nucleotides long excluding the poly(A) tail, and has a single open reading frame encoding a polyprotein. The polyprotein contains three highly conserved domains of UDP glucose/sterol glucosyltransferase, RNA-dependent RNA polymerase, and viral RNA helicase. In addition, particular residues of Cys, Hys, and Gly detected in the N-terminal region suggest the presence of the catalytic site of a highly diverged papain-like protease. Genomic organization, presence of particular conserved motifs, and phylogenetic analyses based on multiple alignments clearly grouped FodHV2 with the members of the family Hypoviridae. FodHV2 was transferred by hyphal anastomosis to a recipient HygR-tagged virus-free strain. The comparison of the infected and non-infected isogenic strains showed that FodHV2 did not alter the vegetative growth, neither the conidiation nor the virulence of its fungal host. Efficiency of FodHV2 transmission through the conidia was 100% in both the original and the recipient infected-isolates. To the best of our knowledge, this is the first report of a hypovirus infecting the plant pathogen F. oxysporum, and also the first one of a hypovirus detected in a fungal strain from the African continent.

中文翻译：

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在尖孢镰刀菌中鉴定出的第一种低病毒的分子和生物学特征。

一种新型真菌病毒，名为尖孢镰刀菌 f。sp。石竹低病毒 2 (FodHV2) 已被鉴定可感染尖孢镰刀菌 (Fusarium oxysporum f) 的 Fod 408 和 Fod 409 分离株。sp。来自摩洛哥的石竹。FodHV2的基因组长9,444个核苷酸，不包括poly(A)尾，并且具有编码多蛋白的单个开放阅读框。该多蛋白含有三个高度保守的结构域：UDP 葡萄糖/甾醇葡萄糖基转移酶、RNA 依赖性 RNA 聚合酶和病毒 RNA 解旋酶。此外，在 N 末端区域检测到的 Cys、Hys 和 Gly 的特定残基表明存在高度分化的木瓜蛋​​白酶样蛋白酶的催化位点。基因组组织、特定保守基序的存在以及基于多重比对的系统发育分析清楚地将 FodHV2 与低病毒科成员分组。FodHV2 通过菌丝吻合术转移至受体 HygR 标记的无病毒菌株中。感染和未感染等基因菌株的比较表明，FodHV2 不会改变其真菌宿主的营养生长、分生孢子形成和毒力。FodHV2 通过分生孢子传播的效率在原始感染菌株和受体感染菌株中均为 100%。据我们所知，这是第一份感染植物病原体尖孢镰刀菌的低病毒的报告，也是在非洲大陆的真菌菌株中检​​测到的第一个低病毒。