转Bt基因棉花的研究应用及问题与对策

20世纪80年代初Bt毒蛋白基因被克隆并转化到植物当中,转Bt基因棉花的应用已取得了相当的效益。但随着转Bt基因棉花的种植,也出现了许多问题,诸如抗药性的产生、抗虫谱狭窄、表达水平低等。现在转抗虫基因棉花的研究主要围绕着转多基因抗虫棉的培育,采用特异启动子调控外源抗虫基因在棉株体内的高效表达,修饰Bt基因以改善Bt毒蛋白的杀虫效能,重视外源与内源抗虫系统间的协调性,加强现代基因工程与传统抗虫育种相结合和筛选广谱性抗虫基因培育广谱性抗虫棉花,等等。

Bt Transgenic Cotton and Its Application in Breeding

In the early 1980s of 20th Century, Bt toxin protein gene had been successfully cloned, and transformed into the plant. Bt transgenic cotton had been developed, which is also one of the first transgenic crops to be planted in large scale in the world where it has been a commercial success less than ten years. With Bt cotton planting, many problems has been appeared, e.g., tolerance of insects to Bt toxin, few range of insects killed by Bt protein, the low level expression of Bt gene in cotton, the difference of time and location of Bt gene expression,and the safety about transgene cotton. The above troublesome might be absolved through various combination of methods and ideas. At present, the results suggested that several genes whose possess different mechanisms of insect-resistance are introduced into plants, special promoters are adopted to locality the protein and to increase the level of target gene expression, factors of physical and chemical regulate the expression of target gene, modification of the sequence of Bt gene increase the level of Bt protein, the external and internal insect-resistant system are taken into account, and the combination of gene engineering and tradition breeding develop many cultivars which have a high efficiency in insect-resistance.