幽影病毒属病毒的研究现状与展望

幽影病毒是一类较为特殊的植物病毒,其基因组不编码外壳蛋白,因此不形成通常的病毒粒体结构。这类病毒可以通过机械摩擦方式传播,在黄症病毒的帮助下也可以通过蚜虫传播。幽影病毒属病毒由7个确定种和3个暂定成员组成,烟草丛顶病毒是目前国内发现的幽影病毒属唯一成员。幽影病毒的寄主范围较窄,体外抗性也较差。幽影病毒感病组织中含有大量dsRNA。有些病毒还含有卫星RNA。幽影病毒的基因组为单分体的 ssRNA,编码4个非结构蛋白,其中的ORF3蛋白在病毒RNA的稳定性及寄主体内的长距离运输中起到非常重要的作用。文章综述了国内外幽影病毒的研究现状,并对未来的相关研究趋势和研究领域进行了展望。

Current situation and prospect of studies on genus Umbravirus

Umbraviruses are a group of imperfectly characterized plant viruses, which are distinguished from most other viruses by their genomes lack of a gene for coat protein (CP), and as a result umbraviruses do not form conventional virus particles. Umbraviruses are mechanically transmissible, and can be aphid transmitted in the persistent manner by an unrelated assistor virus, which is always a member of the family Luteoviridae. In nature, each umbravirus depends for survival on one particular luteovirus.The genus Umbravirus comprises seven distinct virus specieses and three tentative members. Only Tobacco bushy top virus(TBTV) has been reported in China as an umbravirus. Tobacco bushy top disease, caused by TBTV and its helper, Tobacco vein distorting virus(TVDV), which resulted in severe tobacco losses in western of Yunan. Umbraviruses had a restricted host range in nature, and their infectivity and longevity in vitro are not so stable. Plants infected umbraviruses contain abundant double-stranded RNA(dsRNA), and some umbraviruses possess one or more additional dsRNA species associated with the presence of a satellite RNA. The genomes of the umbraviruses consist of one linear segment of positive sense single-stranded RNA(ssRNA), and the nucleotide sequences possess ORFs for four potential non-structural protein products. The umbravirus-encoded ORF3 proteins play essential roles in stabilization of viral RNA and mediation of its long-distance movement. The current research progresses have been reviewed detailly, and the future research tendency and research fields about umbraviruses and umbravirus-caused diseases are put forward.