转Bt基因棉Bt毒蛋白表达量的时空变化

On the Temporal and Spatial Expressions of Bt Toxin Protein in Bt Transgenic Cotton

采用抗体夹心 EL ISA技术 ,对转 Bt基因抗虫棉植株中 Bt毒蛋白含量进行了测定。结果表明 ,Bt基因在所有检测到的器官中均有表达 ,但是不同器官中的 Bt毒蛋白含量明显不同。在苗期全展功能叶中 Bt毒蛋白含量最高 ,根、茎和叶柄中 Bt毒蛋白含量较低 ;在花铃期当日开花的子房中 Bt毒蛋白含量较高 ,雌雄蕊中 Bt毒蛋白较低 ,花瓣及苞叶 Bt毒蛋白含量最低。表明 Bt基因在不同器官中的表达强度存在差异。不同生育期的功能叶中 Bt毒蛋白含量差异显著 ,Bt毒蛋白含量在苗期叶片中最高 ,蕾期次之 ,花铃期最低。随着棉花生长发育进程的推进 ,Bt基因在叶片中的表达强度逐渐减弱。Bt基因在棉花体内的表达随着器官的不同、生育时期的不同而表现出时空动态变化。这可能是人们所观察到的转 Bt基因抗虫棉对棉铃虫抗性呈时空动态变化的根本原因。

By applying antibody sandwich enzyme linked immunosorbent assay method,the content of Bt (Bacillus thuringiensis Berliner) toxin protein in the Bt transgenic cotton was tested. The results showed that Bt toxin protein was detected in all the test organs of the transgenic cotton ,but its contents varied significantly among different organs in different stages. The highest content occurred in the fully expanded leaves in seedling stage, while those in root , stem , petiole in the same stage were rather low. In flowering boll stage , much higher content occurred in ovary on the day of flowering ,but those in pistil and stamen were lower , and those in petal and bract were the lowest .There were significant differences of Bt toxin protein contents among the functional leaves in different stages, the order of content was seedling>quaring>flowering boll. Consequently, The expression of Bt toxin protein in Bt transgenic cotton decreased with advance of development .It shoud be the reason why the resistance of Bt transgenic cotton to cotton bollworm (Helicoverpa armigera (Hübner)) changed temporally and spatially in cotton developmental processes.