孙少双　王冬雪　杨秀玲　周雪平

摘要 双生病毒是一类在全球范围内危害嚴重的单链环状DNA病毒。本研究从2017年采自云南的胜红蓟样品中（YN2017）获得了一条菜豆金色花叶病毒属病毒和一条β卫星的全基因组序列。该双生病毒的全长序列与烟草曲茎病毒的相似性最高，为99.60%，确定为烟草曲茎病毒的分离物。YN2017 β卫星与中国胜红蓟黄脉β卫星的同源性最高，为90.8%。进一步分析发现，该β卫星的卫星保守区域（SCR）至富含腺嘌呤区（A-rich区）之间约1 kb的序列与中国胜红蓟黄脉β卫星相应序列的相似性高达97.2%;其包含的A-rich区上游与SCR之间约300 bp的序列与中国胜红蓟黄脉β卫星相应序列的相似性仅为70.2%，而与烟草曲茎β卫星相应序列的相似性最高，为97.3%。重组分析发现，所分离的β卫星是由中国胜红蓟黄脉β卫星和烟草曲茎β卫星重组产生。这是首次在中国发现由不同的β卫星重组产生的β卫星分子。

关键词 胜红蓟; 双生病毒; β卫星; 重组

中图分类号：

S 432.41

文献标识码： A

DOI： 10.16688/j.zwbh.2019253

Identification of a recombinant geminivirus-associated betasatellite from Ageratum conyzoides

SUN Shaoshuang， WANG Dongxue， YANG Xiuling*， ZHOU Xueping

（State Key Laboratory for Biology of Plant Diseases and Insect Pests， Institute of Plant Protection， Chinese Academy of Agricultural Sciences， Beijing 100193， China）

Abstract

Geminiviruses are a group of single-stranded DNA viruses that cause severe losses to many crops worldwide. In this study， we determined the complete nucleotide sequences of a begomovirus and a betasatellite from an Ageratum conyzoides plant （YN2017） showing yellow vein and leaf curling symptoms in Yunnan. The begomovirus shared 99.60% sequence identity with Tobacco curly shoot virus （TbCSV）and thus was identified as an isolate of TbCSV. The YN2017 betasatellite shared the highest sequence identity （90.8%） with Ageratum yellow vein China betasatellite （AYVCNB）. Further analysis of the betasatellite sequences showed that the sequences from the satellite conserved region （SCR） to the A-rich region shared 97.2%identity with the homologous sequences of AYVCNB， while the sequences between the SCR and the upstream A-rich region only shared 70.2%identity with that of AYVCNB. Instead， these sequences were more closely related （97.3%sequence identity） to the coordinated sequences of TbCSB. Recombination detection analysis showed that the betasatellite might result from the recombination of AYVCNB and TbCSB. This is the first report of a recombinant betasatellite that has arisen from betasatellites recombination in China.

Key words

Ageratum conyzoides; geminivirus; betasatellite; recombination

双生病毒是一类具有孪生颗粒形态的单链环状DNA病毒，病毒粒子大小为18 nm×30 nm。基于基因组结构、介体种类和寄主范围，2017年国际病毒分类委员会（International Committee on Taxonomy of Viruses， ICTV）将双生病毒科分为9个属和2个暂定种，分别为玉米线条病毒属Mastrevirus、菜豆金色花叶病毒属Begomovirus、甜菜曲顶病毒属Curtovirus、番茄伪曲顶病毒属Topocuvirus、美杜莎潜隐病毒属Capulavirus、画眉草条纹病毒属Eragrovirus、伊朗甜菜曲顶病毒属Becurtovirus、芜菁曲顶病毒属Turncurtovirus和葡萄红色斑点病毒属Grablovirus以及桑花叶型矮缩相关病毒和柑橘褪绿矮缩病毒[1]。其中，种类最多、造成危害最严重的是由烟粉虱以持久性方式传播的菜豆金色花叶病毒属病毒。……