为了探讨棉花过表达SOD基因的遗传效应,利用GenBank数据库中棉花胞质SOD基因的核酸序列,设计1对特异引物,克隆了棉花胞质Cu/Zn-SOD基因,构建了植物双元表达载体;采用农杆菌介导的子叶腋芽遗传转化新技术,获得了过量表达的转基因棉花植株.利用PCR扩增报告基因和Southern Blotting证明目标基因已经整合到棉花基因组上;转基因材料T1种子的耐盐性发芽试验表明,在NaCl胁迫下,与对照(非转基因)相比,转基因材料主根平均长度、芽平均长度和侧根平均数量均大于阴性对照,转基因植株与阴性对照相比,转基因植株叶片的MDA含量明显降低,叶绿素总量增加,脯氨酸含量略降低,SOD活性明显提高;转基因植株荧光定量PCR扩增证实目标基因在转基因材料中呈现组成性表达.在棉花中过量表达胞质Cu/Zn-SOD基因,能增加植株SOD活性,减轻盐分胁迫造成的细胞膜质过氧化,增强植株抵御盐分胁迫的能力.%In order to explore the genetically modified effects of excessive expression of superoxide dismutase in the upland cotton. Cotton cytoplasmic superoxide dismutase gene sequences of nucleic acids was found in the Gen-bank database, a pair of specific primers were designed, the cotton cytoplasmic superoxide dismutase gene was cloned and the plant binary expression vector was built,the excessive expression of transgenic cotton plants were ob-tained by used a new technology of cotyledon axillary bud of Agrobacterium mediated genetic transformation. PCR and Southern Blot analysis indicated that the new copy Cu/Zn-SOD gene had been integrated into the genome of cotton. Germination experiment of genetically modified materials T1 generation seeds showed that under the stress of NaCl,the average length of taproot,bud average long and average number of lateral root of genetically modified ma-terials were greater than the negative control, the SOD activity in transgenic plants leaves were significantly im-proved than that in the control,so were the chlorophyll contents,the MDA content was dramatically declined,but praline contents was no changed. If excessive cytoplasmic SOD genes were expressed in the cotton,the SOD activity of plantlet can be increased,this can reduce salt stress caused by the cell membrane peroxidation,and enhance the ability of plants to resist salt stress.
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