文献类型： 外文期刊

第一作者： Han, Zhenhao

作者： Han, Zhenhao;Liu, Jiwen;Kong, Linghong;He, Yunqiang;Xu, Wenxing;Han, Zhenhao;Liu, Jiwen;Kong, Linghong;He, Yunqiang;Xu, Wenxing;Han, Zhenhao;Liu, Jiwen;Kong, Linghong;He, Yunqiang;Xu, Wenxing;Han, Zhenhao;Liu, Jiwen;Kong, Linghong;He, Yunqiang;Xu, Wenxing;Wu, Hongqu;Wu, Hongqu

作者机构：

期刊名称：PLOS PATHOGENS （ 影响因子：6.7； 五年影响因子：6.7 ）

ISSN： 1553-7366

年卷期： 2023 年 19 卷 6 期

页码：

收录情况： SCI

摘要： Author summaryA novel hypovirus belonging to the genus Alphahypovirus of the family Hypoviridae was identified in a phytopathogenetic P. fici isolated from a tea leaf and tentatively named Pestalotiopsis fici hypovirus 1 (PfHV1), which represents the first hypovirus from Pestalotiopsis fungi. Three RNA components (RNA 1 to 3 termed according to their decreasing sizes, dsRNA 1 to 3 termed for their replicative form are corresponding with RNA 1 to 3) associated with PfHV1 including the genomic RNA, defective RNA and satellite-like RNA (SatL-RNA) were determined, and their molecular and biological traits were characterized. The SatL-RNA negatively regulates the accumulation of PfHV1 RNA1, and represents a novel class of satellite nucleic acids since it has substantial sequence homology with the host viral genome and is not encapsidated in the coat protein of its helper virus. This study contributes to our better understanding of fungal satellites, as well as the molecular and biological traits of hypoviruses. Satellites associated with plant or animal viruses have been largely detected and characterized, while those from mycoviruses together with their roles remain far less determined. Three dsRNA segments (dsRNA 1 to 3 termed according to their decreasing sizes) were identified in a strain of phytopathogenic fungus Pestalotiopsis fici AH1-1 isolated from a tea leaf. The complete sequences of dsRNAs 1 to 3, with the sizes of 10316, 5511, and 631 bp, were determined by random cloning together with a RACE protocol. Sequence analyses support that dsRNA1 is a genome of a novel hypovirus belonging to genus Alphahypovirus of the family Hypoviridae, tentatively named Pestalotiopsis fici hypovirus 1 (PfHV1); dsRNA2 is a defective RNA (D-RNA) generating from dsRNA1 with septal deletions; and dsRNA3 is the satellite component of PfHV1 since it could be co-precipitated with other dsRNA components in the same sucrose fraction by ultra-centrifuge, suggesting that it is encapsulated together with PfHV1 genomic dsRNAs. Moreover, dsRNA3 shares an identical stretch (170 bp) with dsRNAs 1 and 2 at their 5 ' termini and the remaining are heterogenous, which is distinct from a typical satellite that generally has very little or no sequence similarity with helper viruses. More importantly, dsRNA3 lacks a substantial open reading frame (ORF) and a poly (A) tail, which is unlike the known satellite RNAs of hypoviruses, as well as unlike those in association with Totiviridae and Partitiviridae since the latters are encapsidated in coat proteins. As up-regulated expression of RNA3, dsRNA1 was significantly down-regulated, suggesting that dsRNA3 negatively regulates the expression of dsRNA1, whereas dsRNAs 1 to 3 have no obvious impact on the biological traits of the host fungus including morphologies and virulence. This study indicates that PfHV1 dsRNA3 is a special type of satellite-like nucleic acid that has substantial sequence homology with the host viral genome without encapsidation in a coat protein, which broadens the definition of fungal satellite.

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