Data from: Stacked Bt maize and arthropod predators – exposure to insecticidal Cry proteins and potential hazards

Genetically engineered (GE) crops with stacked insecticidal traits expose arthropods to multiple Cry proteins from Bacillus thuringiensis (Bt). One concern is that the different Cry proteins may interact and lead to unexpected adverse effects on non-target species. Bi- and tri-trophic experiments with SmartStax maize, herbivorous spider mites (Tetranychus urticae) and aphids (Rhopalosiphum padi), and predatory spiders (Phylloneta impressa), ladybeetles (Harmonia axyridis), and lacewings (Chrysoperla carnea) were conducted. Cry1A.105, Cry1F, Cry3Bb1, and Cry34Ab1 moved in a similar pattern through the arthropod food chain. In contrast, Cry2Ab2 had highest concentrations in maize leaves, but lowest in pollen, and lowest acquisition rates by herbivores and predators. While spider mites contained Cry protein concentrations exceeding the values in leaves (except Cry2Ab2), aphids contained only traces of any Cry protein. Predators contained lower concentrations than their food. Among the different predators, ladybeetle larvae showed higher concentrations than lacewing larvae and juvenile spiders. Acute effects of SmartStax maize on predator survival, development, and weight were not observed. The study thus provides evidence that the different Cry proteins do not interact in a way that poses a risk to the investigated non-target species under controlled laboratory conditions.带有叠加杀虫性状的转基因（Genetically Engineered, GE）作物会使节肢动物暴露于多种苏云金杆菌（Bacillus thuringiensis, Bt）来源的Cry蛋白中。当前研究的核心担忧之一为：不同Cry蛋白之间可能发生相互作用，进而对非靶标物种产生意料之外的不利影响。本研究针对SmartStax玉米、植食性叶螨（二斑叶螨Tetranychus urticae）与麦长管蚜（Rhopalosiphum padi），以及捕食性蜘蛛（球腹蛛Phylloneta impressa）、异色瓢虫（Harmonia axyridis）和普通草蛉（Chrysoperla carnea）开展了二营养级与三营养级实验。Cry1A.105、Cry1F、Cry3Bb1及Cry34Ab1在节肢动物食物链中的迁移模式较为相似。与之形成鲜明对比的是，Cry2Ab2在玉米叶片中浓度最高，但在花粉中浓度最低，且被植食者与捕食者获取的速率也最低。尽管叶螨体内的Cry蛋白浓度（Cry2Ab2除外）均高于玉米叶片，但蚜虫体内仅能检测到极微量的各类Cry蛋白。捕食者体内的蛋白浓度均低于其摄食的食物源。在各类捕食者中，异色瓢虫幼虫体内的蛋白浓度高于草蛉幼虫与幼蛛。本研究未观测到SmartStax玉米对捕食者的存活、发育及体重产生急性影响。综上，本研究提供了相关证据，表明在受控实验室条件下，不同Cry蛋白之间不会以对所研究的非靶标物种构成风险的方式发生相互作用。