昆虫对Bt杀虫蛋白的抗性机制及治理策略

转Bt基因抗虫作物在害虫综合防治中发挥重要作用，是新一代植物保护产品，其抗虫性能和经济效益已得到普遍肯定。然而由于转基因抗虫植物在整个生育阶段高水平的表达Bt杀虫蛋白，有可能会导致害虫对Bt杀虫蛋白产生抗性，抗性的产生将严重影响Bt植物的应用。田间已经发现小菜蛾Plutella xylostella（Linnaeus）对Bt杀虫剂产生了抗性，实验室人工汰选条件下已经有多种害虫对Bt杀虫蛋白产生了抗性，并对抗性产生的机制进行了研究，目前主要认为害虫产生抗性与杀虫蛋白与中肠细胞上受体蛋白结合能力的改变以及Bt杀虫蛋白在中肠的水解作用的变化有关，但抗性产生的机制还与其它因素有关，估计是多方面因素造成的，因此，抗性机制的产生还不十分清楚。目前已经制订了“高剂量＋庇护所”和多基因策略等一系列有效抗性治理策略，这些策略还需要在深入研究并阐明抗性机制的基础上，进一步完善，以实现Bt抗虫植物在害虫防治中的可持续利用。

The mechanism of insect resistance to Bt toxin and the resistance management tactics

Bt-transgenic crops are the new generation plant protection products, which play a great role in integrated pest management. It is a common fact that the Bt-transgenic crops possess high resistance to pests and increase the economic benefits. However, the expression of Bt toxins in Bt crops at a high level during the entire growing season may lead to resistance evolution. Plutella xylostella (Linnaeus) is the only one insect that has evolved resistance to Bt in the field. Many insect species selected under laboratory conditions have evolved resistance to Bt toxin. The mechanisms of resistance evolution reported are related to the alteration of binding Bt toxin to the receptor in midgut membranes and the changes in midgut proteolytic activity of the Bt toxin. The mechanisms of resistance may be correlated with many other factors. Although a series of resistance management strategies such as the high-dose/refuge and multiple toxins have been effective. It is desiderated to solve for further understanding of resistance mechanisms and improving resistance management strategies to ensure Bt-transgenic crops long-term sustainability and maximize their benefits.