黄瓜花叶病毒小青菜分离物RNA3全长序列分析

Full-length sequence analyses of CMV-YN genomic RNA 3 isolated from Brassica compestris ssp.chinensis(L.) Makino

对侵染十字花科小青菜的黄瓜花叶病毒YN分离物(CMV-YN)RNA3进行全长克隆和序列分析.CMV-YNRNA3全长2 220 nt,分别编码279个氨基酸的3a蛋白和218个氨基酸的CP.序列同源性比较结果如下:CMV-YNRNA3核苷酸及其编码蛋白的氨基酸序列与亚组IA株系CMV-Fny、亚组IB株系CMV-Nt9、亚组II株系CMV-Q的同源性,RNA3序列分别为92.7%、96.7%、74.2%,3a蛋白氨基酸序列分别为96.4%、98.6%、83.2%,CP氨基酸序列分别为97.7%、98.2%、83.1%.该结果表明CMV-YN与亚组IB株系CMV-Nt9的同源关系更密切.对CP核苷酸序列的系统进化树分析表明:CMV-YN归属于亚组IB.本研究为首次报道侵染我国十字花科植物的CMV基因组序列.

The full-length cDNA clone of genomic RNA 3 of a Cucumber mosaic virus （CMV） isolate, named CMV-YN, obtained from Brassica compestris ssp. chinensis （L.） Makino, family Cruciferae was created by RT-PCR,and its sequence data were analyzed. The full length of YN RNA 3 was composed of 2 220 nt with two ORFs, encoding 3a protein and CP, respectively. The 3a protein consisted of 279 amino acids,and CP was found consisting of 218 amino acids. The sequence similarities of CMV-YN RNA 3 with the corresponding RNA 3 of CMV-Fny, CMV-Nt9, CMV-Q, from subgroup IA, IB, Ⅱ, respectively, were listed as follows： 92.7%, 96.7%, 74. 2%, respectively; The amino acid sequence similarities of CMV-YN 3a protein and CP with the corresponding proteins of the above three strains were 96.4% 97.7%, 98.6% 98.2%, 83.2% 83. 1%, respectively. CMV-YN was found to be more closely related with CMV-Ntg, belonging to subgroup IB than strains of other subgroups based on the above analyses. The results of phylogenetic analyses on CP gene indicated that CMV-YN was divided into CMV subgroup IB. This is the first report of sequence analyses for CMV infecting Cruciferae in China.