关键词: 芜菁花叶病毒, 外壳蛋白基因, 序列分析, 转基因大白菜

Abstract: Six isolates of turnip mosaic virus named TuMV-SD1, TuMV-SD2, TuMV-SD3, TuMV-SD4, TuMV-SD5, and TuMV-SD6 were isolated from infected Chinese cabbages and radishes in three different regions (Taian, Yantai, and Zaozhuang) in Shandong province. A pair of primers was designed and synthesized based on the nucleotide sequences of coat protein (CP) genes of TuMV reported. The CP genes of the six TuMV isolates were cloned by RT-PCR method. The sequences of all the CP genes from the six isolates were sequenced and compared with the CP gene sequences of TuMV reported in GenBank. The results showed that the sequences of the six CP genes were all 867 nucleotides in length, and the isolates shared high sequence homology from 97.0% to 99.4% among them. They also shared high homologies of 91.8% to 100% with the sequences of world-B group isolates, of 89.1% to 91.0% with the sequences of Brassica-Raphanus (BR) pathotype isolates, and of 86.0% to 90.3% with the sequences of basal-B group isolates. TuMV isolates reported so far were devided into four groups based on phylogenetic analysis of the CP gene sequences. All the six isolates analysized in this study belonged to the fourth group, i.e. world-B group. Resistance assay revealed that the transgenic Chinese cabbage containing a CP gene of TuMV was resistant to infections of all the six isolates, although the CP transgene only shared a homology of less than 90%with the CP genes of the six TuMV isolates.

Key words: TuMV, Coat protein, Sequence analysis, Transgenic Chinese cabbage