摘要
Soybean mosaic virus (SMV) causes one of the most severe viral diseases in soybean ( Glycine max L.) and is known to contain many pathogenically and serologically related isolates. In the present study, the authors have obtained cDNAs to all cistrons of a Chinese SMV isolate, SMV_ZK, by RT_PCR. By analysing the nucleotide and amino acid sequence of the HC_PRO, NIb and CP cistrons, it was found that SMV_ZK was highly homologous to the G2 strain of SMV, thus confirming the existence of G2_like isolates in soybean crop in China. The amplified cDNAs were directly cloned into a bacterial expression vector. With the exception of the P3 cistron, expression of the cDNAs of all other cistrons in bacteria gave rise to polypeptides of expected molecular weight. The expressed viral proteins were subsequently purified by gel elution. The preparation of viral_specific cDNAs and gene products will be useful in future functional study of the SMV genome.
大豆花叶病毒（ＳＭＶ） 在大豆（ Ｇｌｙｃｉｎｅ ｍａｘ Ｌ．） 上引起严重病害。利用ＲＴ＿ＰＣＲ 扩增并克隆了ＳＭＶ＿ＺＫ（ 一个中国ＳＭＶ 分离株） 基因组中全部蛋白质编码区的ｃＤＮＡ。通过对ＨＣ＿ＰＲＯ、ＮＩｂ 和ＣＰ编码区进行序列测定与分析，发现ＳＭＶ＿ＺＫ 与ＳＭＶ＿Ｇ２ 高度同源，从而在分子水平上证明在我国大豆作物中存在ＳＭＶ＿Ｇ２ 类似株系。将ＳＭＶ＿ＺＫｃＤＮＡ克隆于细菌表达载体，获得并提纯了６ 种ｃＤＮＡ 的表达产物。这项工作将为进一步研究ＳＭＶ 基因组的功能奠定基础。
