摘要
转金属硫蛋白ＭＴ及其突变体αα的烟草自交得到Ｔ１代，转基因植株的重金属抗性和除草剂抗性在后代中得到保持。不同的转基因株系在含有除草剂的培养基中萌发时表现出不同的抗性分离比，说明外源基因在植物染色体内可能有不同的整合拷贝数。两种转基因烟草在含有不同浓度Ｃｄ的培养基中萌发时表现出高的重金属抗性，其中转αα基因烟草对Ｃｄ的抗性优势在Ｔ１代种子萌发实验中更加明显。以ＭＴ ｃＤＮＡ为探针进行ｓｏｕｔｈｅｒｎ ｂｌｏｔ杂交，在Ｔ０代和Ｔ１代同时检测到两种转基因烟草外源基因的存在，证明外源基因确实整合到烟草基因组内并稳定传递到后代。Ｗｅｓｔｅｒｎ ｂｌｏｔ结果证明了外源基因在烟草第二代的表达。纯合株系仍需要进一步的筛选。
The chimeric gene containing a cloned mouse metallothionein processed gene or a cloned mouse metallothionein domain mutantαα gene was respectively introduced into tobacco (Nicotiana tobacum L. cv. NC89) on a disarmed Ti-plasmid of Agrobacterium tumefaciens. T1 seeds from self-fertilized transgenic tobacco were germinated on media containing cadmium or herbicide PPT. The PPT tolerance trait followed Mendelian inheritance and co-segregated with heavy metal tolerance. Meanwhile Southern blot and Western blot verified the existence of the MT gene and αα mutant gene in the T1 generation plants which keep tolerance to heavy metal. All the results demonstrated the stable integration and inheritance of exotic genes. In addition, assay of the root length and fresh weight of T1 seedlings indicate that transgenic tobacco plants withαα mutant gene still have a little higher tolerance than that with matural MT gene.
基金
国家高技术发展计划项目(批准号:863-103-21-09)~~
