中文摘要：

本研究是将从野大豆盐碱胁迫基因表达谱中筛选得到的GsGST13基因和采用生物信息学方法改造的高甲硫氨酸蛋白基因SCMRP构建成双价植物表达载体,通过农杆菌介导法转化农菁1号苜蓿,获得超量表达的转基因苜蓿,并对其中2个转基因苜蓿株系进行耐盐性分析及氨基酸组分分析.结果显示,转基因苜蓿具有较强的耐盐性,表现为随着盐浓度的升高,野生型苜蓿盐害不断加重,生长发育受抑制,叶片逐渐变黄、卷曲、萎蔫,而转基因苜蓿只受到轻微影响,仍能正常生长.转基因株系的丙二醛含量和过氧化氢含量显著低于非转基因株系（P＜0.05）,而株高,鲜重,GST活性和SOD活性显著高于非转基因对照（P＜0.05,P＜0.01）;同时株系G16和G50的含硫氨基酸含量分别比野生型植株提高了0.57％和0.52％.说明超量表达GsGS T13/SCMRP基因增强了苜蓿的耐盐性,并提高了含硫氨基酸含量.

英文摘要：

The GsGST13 gene was selected based on the Glycine soja gene transcriptome of salt-alkaline stress.The high-sulfur-containing amino acids gene SCMRP was designed using the bioinformatics codes.The plant binary expression vector （pBEOGST13/SCMRP） was designed and transferred into alfalfa （Medicago sativa cv.Nongjing No.1） using the Agrobacterium mediated method.Many over-expression transgenic alfalfa lines were obtained,and two of them were selected to analyse the salt resistance and sulfur amino acids contents.Transgenic alfalfa lines showed enhanced tolerance to NaC1 stress compared with wild-type plants.Under NaCl stress,the growth of wild-type plants was inhibited,the blade gradually became yellow and crimp panama,but there was only a slight effect on the transgenic lines,which had normal growth under stress.The malondialdehyde and hydrogen peroxide contents of transgenic lines were significantly lower than those of non-transgenic lines （P＜0.05）.Moreover,plant height,fresh weight,GST activity and SOD activity of transgenic alfalfa were significantly （P＜0.05,P＜0.01 respectively） higher than those of non-transgenic lines under salt stress conditions.Further,the sulfur amino acids contents of the G16 and G50 transgenic alfalfa lines were higher than those of wild type plants,by 0.57％ and 0.52％,respectively.Over-expression of the GST13 and SCMRP in alfalfa improved the tolerance to salinity stress and increased the content of sulfur amino acids.