侵染花生的黄瓜花叶病毒CA株核酸全序列分析

Full Sequence Analyses of Genomic RNAs of Cucumber Mosaic Virus CA Strain Infecting Peanut in China

对侵染花生的黄瓜花叶病毒CA(CMVCA)株系进行克隆和序列分析。CMVCARNA1全长3356个核苷酸(nt),编码分子量为111kDa的1a蛋白;RNA2全长3045nt,编码分子量为96.7kDa的2a蛋白和13.1kDa的2b蛋白;RNA3全长2219nt,编码分子量为30.5kDa的3a蛋白和分子量为24kDa的外壳蛋白(CP)。序列同源性比较表明,CMVCARNA1、2、3与CMV亚组IACMVFny、亚组IBCMVSD、亚组IICMVQ株系序列同源性,RNA1分别为91.3%、91.1%和76.5%,RNA2分别为92.1%、90%和71.2%,RNA3分别为96.1%、92.6%和74.5%;与同属花生矮化病毒(Peanutstuntvirus,PSV)RNA1、2、3序列同源性分别为67.1%、58.2%和55.7%。上述研究未发现CMVCA基因组与PSVRNA链的重组,CMVCA对花生的侵染应是该株系适应于花生的遗传变异、长期进化的结果;对RNA35′NTR结构分析以及RNA35′NTR和CP系统进化树分析表明,CMVCA属CMVIB亚组。

The nucleotide sequences of full length RNAs of CMV-CA strain were determined and compared with those of CMV-Fny in subgroupⅠA, CMV-SD in subgroupⅠB and CMV-Q in subgroupⅡ, and Peanut stunt virus(PSV) ER strain in the same genus. CMV-CA RNA1 is 3356nt long,containing 1 ORF encoding 111kDa 1a protein; RNA2 is 3045nt,containing 2 ORFs encoding 96.7kDa 2a and 13.1kDa 2b proteins, RNA3 is 2 219nt,containing 2 ORFs encoding {30.5}kDa 3a and 24kDa CP. The sequence similarity of CMV-CA RNAs with the corresponding RNAs of CMV SD,Fny,Q strains were as following: RNA1∶91.3%,91.1%,76.5%; RNA2∶92∶1%,90%,71.2%; RNA3∶96.1%,92.6%,74.5%,respectively. The sequence similarity of CMV-CA RNAs with the corresponding RNAs of PSV-ER were 67.1%,58.2% and 55.7% respectively. These results showed that CMV-CA was not the reassortment virus of CMV with PSV, although both of two occur in peanut fields in northern China. Based on RNA3 5′NTR structure, and phylogenetic tree analyses of RNA3 5'NTR nucleotide sequence and CP amino acid sequence, CMV-CA is classified in CMV IB subgroup.