Boss Anja, Romeis Jörg, Meissle Michael
Research Division Agroecology and Environment, Agroscope, Zürich, Switzerland.
Institute of Plant Sciences, University of Bern, Bern, Switzerland.
Insect Sci. 2023 Aug;30(4):1191-1206. doi: 10.1111/1744-7917.13143. Epub 2022 Dec 7.
Genetically engineered (GE) cotton, MON 88702, is protected against certain sucking pests, such as plant bugs and thrips, by producing mCry51Aa2, a modified protein from Bacillus thuringiensis (Bt). Predatory pirate bugs (Orius spp.), natural enemies contributing to biological pest control, are also sensitive to the insecticidal protein when exposed continuously to high concentrations. We evaluated effects of MON 88702 on Orius majusculus when fed prey types with different mCry51Aa2 concentrations. When neonates were provided exclusively Tetranychus urticae spider mites reared on MON 88702 (high mCry51Aa2 content), adverse effects on predator survival and development were confirmed, compared with specimens fed prey from near-isogenic non-Bt cotton. When fed a mixture of T. urticae and Ephestia kuehniella eggs (mCry51Aa2-free), predator life table parameters were similar to the treatment where eggs were fed exclusively. When mCry51Aa2-containing spider mites were provided for a limited time at the beginning or the end of juvenile development, effects were less pronounced. While pirate bug nymphs showed similar consumption rates for prey from Bt and non-Bt cotton, choice experiments revealed a preference for E. kuehniella eggs over spider mites. Lepidopteran larvae (Spodoptera littoralis, high mCry51Aa2 content) or cotton aphids (Aphis gossypii, mCry51Aa2-free) reared on MON 88702 as alternative prey did not result in adverse effects on O. majusculus. Our study suggests limited risk of mCry51Aa2-producing cotton for O. majusculus, because its sensitivity for the Bt protein is relatively low and its natural food consists of diverse prey species with varying concentrations of Bt protein.
转基因棉花MON 88702通过产生mCry51Aa2（一种来自苏云金芽孢杆菌（Bt）的修饰蛋白）来抵御某些刺吸式害虫，如盲蝽象和蓟马。作为有助于生物防治害虫的天敌，捕食性花蝽（ Orius spp.）在持续暴露于高浓度杀虫蛋白时也会对其敏感。我们评估了MON 88702在喂食不同mCry51Aa2浓度猎物类型时对大花蝽（Orius majusculus）的影响。当仅向新生大花蝽提供在MON 88702上饲养的二斑叶螨（Tetranychus urticae）（mCry51Aa2含量高）时，与喂食来自近等基因非Bt棉花的猎物的样本相比，确认对捕食者的存活和发育有不利影响。当喂食二斑叶螨和地中海粉螟（Ephestia kuehniella）卵的混合物（不含mCry51Aa2）时，捕食者生命表参数与仅喂食卵的处理相似。当在幼虫发育开始或结束时有限时间内提供含mCry51Aa2的叶螨时，影响不太明显。虽然花蝽若虫对Bt棉花和非Bt棉花的猎物表现出相似的消耗率，但选择实验表明它们更喜欢地中海粉螟卵而不是叶螨。以MON 88702上饲养的鳞翅目幼虫（滨海灰翅夜蛾（Spodoptera littoralis），mCry51Aa2含量高）或棉蚜（棉蚜（Aphis gossypii），不含mCry51Aa2）作为替代猎物对大花蝽没有产生不利影响。我们的研究表明，产生mCry51Aa2的棉花对大花蝽的风险有限，因为它对Bt蛋白的敏感性相对较低，并且其天然食物由不同浓度Bt蛋白的多种猎物组成。
