广东番茄曲叶病毒G3分离物基因组DNA-A的分子特征  

The molecular characteristics of DNA-A of tomato leaf curl Guangdong virus isolate G3

作　　者：何自福[1] 虞皓[1] 罗方芳[1] 

机构地区：[1]广东省农业科学院植物保护研究所

出　　处：《植物病理学报》2005年第3期208-213,共6页Acta Phytopathologica Sinica

基　　金：广东省自然科学基金(031992);广东省重点实验室二期建设启动项目(2003B60128)

摘　　要：从采集于广东花都的番茄曲叶病病株上分离到病毒分离物ToLCGDV-[G3],序列分析结果表明,其DNA-A为单链环状,全长2744 nt,共有6个ORFs,其中病毒链上编码AV1(CP)、AV2,互补链上编码AC1、AC2、AC3和AC4.BLAST结果显示,与ToLCGDV-[G3]基因组有同源关系的均属双生病毒科菜豆金色花叶病毒属.进一步比较结果表明,ToLCGDV-[G3]与有同源性的菜豆金色花叶病毒属病毒的DNA-A全序列同源率最高为87.9%.其中IR的同源率为59.0%～85.3%,而AW、AV2、AC1、AC2、AC3和AC4这6个ORFs同源率分别为73.6%～95.2%、64.0%～95.4%、71.7%～87.7%、69.6%～93.9%、67.7%～95.1%和64.1%～94.2%,它们各自编码的氨基酸序列同源率分别为76.3%～99.2%、52.6%～95.7%、69.7%～88.1%、51.9%～88.9%、63.4%～92.5%和33.0%～90.7%.系统进化关系分析结果显示,ToLCGDV-[G3]与ToLCGDV-[G2]亲缘关系最近,二者组成一个独立的分支,与其它40种菜豆金色花叶病毒属病毒的亲缘关系均较远.因此,ToLCGDV-[G3]可能是一个先前未报道的双生病毒科菜豆金色花叶病毒属新种.The ToLCGDV- was isolated from tomato plants showing leaf curl symptoms in Guangdong. The complete nucleotide sequence of ToLCGDV- DNA-A was determined. It contains 2744 nucleotides and encodes six potential ORFs, with two (AV1 and AV2) in virion-sense strand and four (AC1, AC2, AC3 and AC4) in complementary strands. BLAST results showed that all sequences homologous to ToLCGDV- DNA-A belonged to the genus Begomovirus of family Geminiviridae. Pairwise comparisons of ToLCGDV- DNA-A with those of other begomoviruses indicated that the overall identities were less than 88.0%. The identities of intergenic region (IR), AV1, AV2, AC1, AC2, AC3 and AC4 were 59.0%-85.3%, 73.6%-95.2%, 64.0%-95.4%, 71.7%-87.7%, 69.6%-93.9%, 67.7%- 95.1% and 64.1%-94.2% respectively, and that of their encoded amino acid sequences were 76.3%-99.2%, 52.6%-95.7%, 69.7%-88.1%, 51.9%-88.9%, 63.4%-92.5% and 33.0%-90.7% respectively. Phylogenetic analysis of DNA-A of ToLCGDV- and the selected begomoviruses showed that ToLCGDV- is most closely related to ToLCGDV-[G2] than the other begomoviruses, and that the two viruses were clustered in a separate branch. These results suggest that ToLCGDV- should be a previously unreported begomovirus.

关 键 词：广东番茄曲叶病毒G3 DNA—A 序列分析 分子特征 

分 类 号：S432.41[农业科学—植物病理学]