State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Agricultural Trade Promotion Center, Ministry of Agriculture and Rural Affairs, Beijing 100125, China.
Viruses. 2020 Mar 24;12(3):357. doi: 10.3390/v12030357.
Fungal viruses (mycoviruses) have attracted more attention for their possible hypovirulence (attenuation of fungal virulence) trait, which may be developed as a biocontrol agent of plant pathogenic fungi. However, most discovered mycoviruses are asymptomatic in their hosts. In most cases, mycovirus hypovirulent factors have not been explored clearly. In this study, we characterized a ssRNA mycovirus in strain HB56-9. The complete nucleotide genome was obtained by combining random sequencing and rapid amplification of cDNA ends (RACE). The full genome was 6621-nucleotides long, excluding the poly(A) tail. The mycovirus was quite interesting because it shared 95.91% nucleotide identities with previously reported Fusarium graminearum virus 1 strain DK21 (FgV1-DK21), while the colony morphology of their fungal hosts on PDA plates were very different. The novel virus was named Fusarium graminearum virus 1 Chinese isolate (FgV1-ch). Like FgV1-DK21, FgV1-ch also contains four putative open reading frames (ORFs), including one long and three short ORFs. A phylogenetic analysis indicated that FgV1-ch is clustered into a proposed family Fusariviridae. FgV1-ch, unlike FgV1-DK21, had mild or no effects on host mycelial growth, spore production and virulence. The nucleotide differences between FgV1-ch and FgV1-DK21 will help to elucidate the hypovirulence determinants during mycovirus-host interaction.
真菌病毒（真菌病毒）因其可能的弱毒（真菌毒力减弱）特性而引起了更多关注，这种特性可能被开发为植物病原真菌的生物防治剂。然而，大多数发现的真菌病毒在其宿主中是无症状的。在大多数情况下，真菌病毒弱毒因子尚未得到明确探索。在本研究中，我们对 HB56-9 菌株中的一种 ssRNA 真菌病毒进行了表征。通过结合随机测序和快速扩增 cDNA 末端（RACE）获得了完整的核苷酸基因组。完整基因组长 6621 个核苷酸，不包括 poly(A)尾。该真菌病毒非常有趣，因为它与先前报道的禾谷镰刀菌病毒 1 株 DK21（FgV1-DK21）的核苷酸同一性为 95.91%，而其真菌宿主在 PDA 平板上的菌落形态却大不相同。该新病毒被命名为禾谷镰刀菌病毒 1 中国分离株（FgV1-ch）。与 FgV1-DK21 一样，FgV1-ch 也包含四个推定的开放阅读框（ORF），包括一个长和三个短 ORF。系统发育分析表明，FgV1-ch 聚类到一个提议的丝状病毒科中。与 FgV1-DK21 不同，FgV1-ch 对宿主菌丝生长、孢子产生和毒力几乎没有或没有影响。FgV1-ch 与 FgV1-DK21 之间的核苷酸差异将有助于阐明真菌病毒-宿主相互作用过程中的弱毒决定因素。
