转BmK IT_4基因烟草的抗虫性

Studies on Insect Resistance of Transgenic Tobacco Plants Carrying the BmK IT_4 Gene

用酶切方法从pBS_BmKIT4 质粒中获得BmKIT4 基因片段 ,并构建CaMV 35S启动子下的BmKIT4 基因表达质粒pE3_BmKIT4 ,以根癌土壤杆菌 (Agrobacteriumtumefaciens (SmithetTownsend)Conn)介导的叶盘法转化云烟 (Nico tianatabacumL .)K32 6叶片 ,获得 45株抗卡那霉素的再生植株。用这些再生植株进行抗虫试验 ,发现有 2株植株对烟草天蛾 (Manducasexta (Linnaeus) )、棉铃虫 (Heliothisarmigera (H櫣ｂｎｅｒ) )和大豆食心虫 (Leguminivoraglycinivorella(Matsumura) )都有较强的抗性。收获这 2株烟草的自交种子后 ,对T1代幼苗进行Southern杂交分析表明 ,BmKIT4基因已转入这些烟草中 ,用这些子代植株进行抗虫试验 ,与对照株相比 ,这 2株转基因烟草对烟草天蛾的杀虫率达95 %～ 97% ,对棉铃虫的杀虫率达 6 3%～ 70 % ,对大豆食心虫的杀虫率达 6 5 %～ 73% ,并能显著抑制昆虫的蜕皮和生长发育 ,表现出强烈的抗虫作用。

The BmK IT 4 gene was obtained from pBS_BmK IT 4 by EcoRⅠ/KpnⅠ digestion and it was then cloned into pE3 intermediate vector. The resulting plasmid was named pE3_BmK IT 4. The chimeric gene was transferred into the tobacco (Nicotiana tabacum L.) genome via Agrobacterium_mediated transformation. Forty_five regenerated kanamycin resistant plants were obtained, two individual lines showed strong toxicity to Manduca sexta (Linnaeus), Heliothis armigera (Hübner) and Leguminivora glycinivorella (Matsumura) by feeding experiments. Results from Southern blot indicated that BmK IT 4 gene was transferred into tobacco genome. The mortality of M. sexta, H. armigera and L. glycinivorella larvae fed on transgenic plants was 95%-97%, 63%-70% and 65%-73%, respectively, and the growth of the surviving insects was remarkably retarded.