Torres-Trenas Almudena, Cañizares M Carmen, García-Pedrajas M Dolores, Pérez-Artés Encarnación
Departamento de Protección de Cultivos, Instituto de Agricultura Sostenible, Consejo Superior de Investigaciones Científicas, Córdoba, Spain.
Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas, Málaga, Spain.
Front Microbiol. 2020 Jan 24;10:3131. doi: 10.3389/fmicb.2019.03131. eCollection 2019.
A novel mycovirus named Fusarium oxysporum f. sp. dianthi hypovirus 2 (FodHV2) has been identified infecting isolates 408 and 409 of f. sp. 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 . FodHV2 was transferred by hyphal anastomosis to a recipient Hyg-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 , and also the first one of a hypovirus detected in a fungal strain from the African continent.
一种名为尖孢镰刀菌香石竹专化型低毒病毒2（FodHV2）的新型真菌病毒已被鉴定出感染来自摩洛哥的香石竹专化型分离株408和409。FodHV2的基因组长度为9444个核苷酸，不包括聚腺苷酸尾，并且有一个单一的开放阅读框编码一个多聚蛋白。该多聚蛋白包含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解旋酶这三个高度保守的结构域。此外，在N端区域检测到的特定半胱氨酸、组氨酸和甘氨酸残基表明存在一种高度分化的木瓜蛋白酶样蛋白酶的催化位点。基于多序列比对的基因组组织、特定保守基序的存在以及系统发育分析清楚地将FodHV2与该科的成员归为一类。FodHV2通过菌丝融合转移到一个带有潮霉素标签的无病毒受体菌株中。对感染和未感染的同基因菌株的比较表明，FodHV2既不改变其真菌宿主的营养生长，也不改变其分生孢子形成或毒力。FodHV2在原始感染分离株和受体感染分离株中通过分生孢子的传播效率均为100%。据我们所知，这是关于一种低毒病毒感染植物病原菌的首次报道，也是在非洲大陆的真菌菌株中检测到的低毒病毒的首次报道。
