Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Ecotoxicol Environ Saf. 2020 Sep 1;200:110719. doi: 10.1016/j.ecoenv.2020.110719. Epub 2020 May 24.
The insecticidal crystal proteins of Cry2A family from Bacillus thuringiensis (Bt) are important candidate proteins expressed in gene pyramiding Bt crops. A transgenic rice line (T2A-1) harboring a synthetic Cry2A* (Cry2Aa) gene showed effective resistance to some lepidopteran rice pests. As a generalist predator in rice ecosystems, the rove beetle (Paederus fuscipes) can prey on many rice insect pests such as planthoppers. Considering the possible exposure of Cry2Aa to P. fuscipes through tritrophic food chain, it is necessary to assess the potential risks of T2A-1 rice to this predator. In this study, a tritrophic experiment was conducted to assess the prey-mediated effects of Cry2Aa on P. fuscipes through the T2A-1 rice-Nilaparvata lugens-P. fuscipes food chain. After preying on N. lugens nymphs reared on T2A-1, no accumulated Cry2Aa could be detected in P. fuscipes adults, despite Cry2Aa being detected in N. lugens. In addition, no harmful effects were detected on the life table parameters of P. fuscipes in this tritrophic chain. Additionally, direct exposure to a high dose of purified Cry2Aa protein, representing the worst case scenario, showed no significant adverse effects on the development of P. fuscipes. These results showed that transgenic Cry2Aa rice had no harmful effects on P. fuscipes.
苏云金芽孢杆菌（Bt）的 Cry2A 家族杀虫晶体蛋白是基因叠加 Bt 作物中表达的重要候选蛋白。含有合成 Cry2A*（Cry2Aa）基因的转基因水稻品系（T2A-1）对一些鳞翅目水稻害虫表现出有效抗性。作为稻田生态系统中的一种广食性捕食者，隐翅虫（Paederus fuscipes）可以捕食许多水稻害虫，如稻飞虱。考虑到 Cry2Aa 可能通过三营养食物链暴露于 P. fuscipes，有必要评估 T2A-1 水稻对这种捕食者的潜在风险。在这项研究中，通过 T2A-1 水稻-褐飞虱-隐翅虫食物链进行了三营养实验，以评估 Cry2Aa 对 P. fuscipes 的捕食介导效应。在取食 T2A-1 上饲养的褐飞虱若虫后，尽管在褐飞虱中检测到了 Cry2Aa，但在隐翅虫成虫中未检测到积累的 Cry2Aa。此外，在这个三营养链中，隐翅虫的生命表参数没有检测到有害影响。此外，直接暴露于高剂量的纯化 Cry2Aa 蛋白（代表最坏情况）对隐翅虫的发育没有显著的不良影响。这些结果表明，转 Cry2Aa 水稻对隐翅虫没有有害影响。
