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利用小麦黄花叶病毒(Wheat yellow mosaic virus, WYMV)潢川分离物连续继代机械接种感病小麦品种鄂恩1号,经继代接种12 代以上的小麦症状明显加重, Northern blot 检测发现一条明显的低分子量病毒RNA1(LMW RNA1),并在随后至26代的继代接种发病材料中稳定存在,但在利用同样病叶提纯的病毒粒子内检测不到LMW RNA1,表明其不能被包装到病毒粒子内。序列分析结果表明,低分子量RNA1 由病毒RNA1 发生内部缺失而产生,从RNA1 5′端非编码区(第68nt)到CI基因编码区的3′端(第2448nt)共缺失2380 个核苷酸,在缺失区域两端的结合位点存在六个碱基的正向重复序列CGTCTC。据此对此低分子量RNA1 的缺失机制进行了讨论,认为由一种模板转换机制导致了缺失的发生。
The wheat yellow mosaic virus (WYMV) Huangchuan isolate was used in succession to mechanically inoculate the susceptible wheat cultivar Ern-1. The symptoms of wheat over 12 generations after inoculation were significantly aggravated. Northern blot showed that a significant Of low molecular weight virus RNA1 (LMW RNA1) and remained stable in the subsequent passage-to-generation 26 inoculated inoculum, however LMW RNA1 was undetectable in virions purified with the same diseased leaves indicating that it could not be packaged into a virus Within the particle. Sequence analysis showed that the low molecular weight RNA1 was generated by the internal deletion of the viral RNA1, a total of 2380 nucleotides were deleted from the 5 ’noncoding region (68nt) of RNA1 to the 3’ end of the CI gene coding region (2448nt) There are six bases forward repeat CGTCTC at the binding sites at both ends of the deletion region. Based on this, the mechanism of deletion of low molecular weight RNA1 was discussed, and it was considered that the deletion mechanism was caused by a template switching mechanism.