中国多年生野生大豆Glycine亚属rbcS基因的结构和系统发生的研究

用PCR法从我国多年生野生大豆Glycine亚属的烟豆 (GlycinetabacinaBenth .)和多毛豆 (短绒野大豆GlycinetomentellaHayata)的总DNA中扩增到Rubisco小亚基基因 (rbcS) ,2个基因的顺序分析结果表明它们包含了 5 37bp长的编码区 ,其编码的 178肽的Rubisco小亚基前体由 5 5个氨基酸组成的前导肽和 12 3个氨基酸组成的成熟肽组成 .基因内有 2个内含子 .比较Glycine亚属内烟豆和多毛豆之间的rbcS间碱基同源性为94 5 % ,差别主要存在于内含子中 ;Soja亚属的G .soja和G .max之间该基因同源性高达 99 7% ,而Glycine亚属和Soja两亚属之间rbcS同源性则为 84 8% .从这 2个亚属内 4个种的rbcS成熟肽 12 3个氨基酸顺序可知 ,同一亚属内 2个种之间仅有 2～ 3个氨基酸不同 ,而Glycine亚属和Soja亚属之间差异增大至 5～ 6个氨基酸 .系统进化树分析也表明Glycine亚属与Soja亚属在进化过程中分离较早 ,这从分子水平上为大豆属的分类研究提供了科学的依据 .

Studies on the Structure and Molecular Phylogensis of rbcS Gene of Perennial Wild Soybean (Glycine L.Subgenus Glycine) in China

The genes of Rubisco small subunit ( rbc S) were amplified from total DNA of two species of subgenus Glycine: G.tabacina Benth. and G.tomentella Hayata, by the means of PCR. The sequence analysis indicated that PCR fragment included the whole coding region for Rubisco small subunit precursor, which was composed of a transit peptide of 55 amino acids and a mature protein of 123 amino acids. Two introns were found in both of the rbc S genes. By comparison, the homology of rbc S between two species of subgenus Glycine (G.tabacina and G.tomentella ) and between two species of subgenus Soja (G.soja and G.max ) are 94.5% and 99.7% respectively. However, the rbc S homology between subgenus Glycine and subgenus soja is significantly lower to 84.8%. Comparison of deduced amino acids sequences of mature protein from 4 species of soybean showed that there were 2 3 amino acids change within subgenus and 5 6 amino acids change between two subgenus. The phylogenetic relationship analysis demonstrated that subgenus Glycine was early separated from subgenus Soja during evolution. The results provided phylogenesis information of Glycine willd in molecular level.