Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Ecotoxicol Environ Saf. 2020 May;194:110380. doi: 10.1016/j.ecoenv.2020.110380. Epub 2020 Mar 4.
Transgenic crops express Cry proteins exhibit high resistant to target insect pests. When we evaluate the effects of Cry proteins on the parasitoid of target insect pest via tritrophic experiments (transgenic plant-target insect pest-parasitoid) host quality of parasitoids might decrease because of insecticidal protein ingestion, this would cause host-quality mediated effects and influence the accuracy of biosafety assessment. In the current study, high dose of Cry2Aa protein was injected into the hemolymph of Plodia interpunctella by microinjection, and the hemolymph was used as the carrier to deliver Cry protein to Habrobracon hebetor, which has been previously reported as an ectoparasitoid of P. interpunctella larval, in order to avoid the "host-quality mediated effects". Results showed that injected Cry2Aa remained at high concentration and bioactive in the hemolymph of P. interpunctella parasitized by H. hebetor, the hemolymph of P. interpunctella could be used as carriers of Cry protein to H. hebetor, and high dose of Cry2Aa have no negative impacts on the development time, weight of pupa, sex ratio, adults weight (male and female), adult longevity and fecundity, and the activity of stress-related enzymes of H. hebetor. However, the hemolymph of P. interpunctella injected into Galanthus nivalis agglutinin (the positive control) showed significant negative impact on these parameters measured in the present study of H. hebetor. This indicated that Cry2Aa protein had no detrimental effects on the biological parameters of H. hebetor measured in the current study. Meanwhile, this study provides a new method for the safety evaluation of the ectoparasitoids of target pest and might be expanded to the other species of ectoparasitoids of target insects of Cry proteins in biosafety risk assessment.
转基因为 Cry 蛋白表达的作物对靶标害虫表现出高抗性。当我们通过三营养级实验（转基因植物-靶标害虫-寄生蜂）评估 Cry 蛋白对靶标害虫的寄生蜂的影响时，由于摄入杀虫蛋白，寄生蜂的宿主质量可能会下降，这将导致宿主质量介导的效应，并影响生物安全评估的准确性。在本研究中，通过微量注射将高剂量的 Cry2Aa 蛋白注入斜纹夜蛾的血淋巴中，并用血淋巴作为载体将 Cry 蛋白传递给已被报道为斜纹夜蛾幼虫外寄生蜂的茧蜂，以避免“宿主质量介导的效应”。结果表明，Cry2Aa 在被茧蜂寄生的斜纹夜蛾血淋巴中保持高浓度和生物活性，斜纹夜蛾的血淋巴可用作 Cry 蛋白传递给茧蜂的载体，高剂量的 Cry2Aa 对茧蜂的发育时间、蛹重、性别比例、成虫体重（雌雄）、成虫寿命和繁殖力以及与应激相关的酶活性没有负面影响。然而，注入到雪花莲凝集素（阳性对照）的斜纹夜蛾血淋巴对本研究中测量的茧蜂的这些参数表现出显著的负面影响。这表明 Cry2Aa 蛋白对本研究中测量的茧蜂的生物参数没有不利影响。同时，本研究为靶标害虫的外寄生蜂的安全性评估提供了一种新方法，并且可以扩展到生物安全风险评估中 Cry 蛋白对其他靶标昆虫的外寄生蜂的其他物种。
