Yao Qiong, Xu Shu, Dong Yizhi, Quan Linfa, Chen Bingxu
Guangdong Provincial Key Laboratory of New High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, China.
Front Physiol. 2020 Jul 17;11:851. doi: 10.3389/fphys.2020.00851. eCollection 2020.
Bradley (Lepidoptera: Gracilariidae) is the dominant insect pest of litchi ( Sonn.) and longan ( Lour.) fruit trees. Management of this pest species is a challenging task due to its cryptic borer behavior. Controlling at the egg stage is the best alternative strategy to chemical control of adults. However, thorough studies regarding the indirect and sublethal effects of chemicals on the different developmental stages of are insufficient. In this study, the effect of some insecticides was evaluated on eggs. The ovicidal activity of chlorbenzuron, abamectin, chlorantraniliprole, and λ-cyhalothrin was confirmed by morphological observation of the defects in eggs. Moreover, we characterized four essential ecdysone receptor proteins in insects [i.e., two isoform ecdysone receptors (EcR: CsEcRA. CsEcRB) and two isoform ultraspiracle proteins (USP: USP1, USP2)] from eggs. The , , , and genes consisted of 1521-, 1614-, 1410-, and 1236-bp open reading frames which encoded proteins of 506, 527, 469, and 413 amino acid residues, respectively. Furthermore, the embryonic differential responses of s, s, and vitellogenin receptor () to insecticides were evaluated by qRT-PCR. Among the five tested genes, and were the most sensitive to all the tested insecticides, with fold change of the expression diminished by 4.27-8.70 times compared with untreated control insects. The data suggests that these insecticidal compounds regulate the expression of these specific proteins, which might eventually lead to reduced viability of eggs. We present here the first data providing molecular elucidation of ecdysone receptor genes and their differential responses to insecticides in eggs. Together with our previous report of insecticide sublethal effects on two reproduction-related genes in adults, and seem to be appropriate molecular parameters for the evaluation of insecticide impact on . This study exemplifies the potential utility of transcriptional measurement of nuclear receptors as the molecular biomarkers for ecotoxicological evaluations of ovicidal impact of insecticides.
布拉德利（鳞翅目：细蛾科）是荔枝（无患子科）和龙眼（无患子科）果树的主要害虫。由于其隐秘的蛀干行为，对这种害虫的管理是一项具有挑战性的任务。在卵期进行防治是替代化学防治成虫的最佳策略。然而，关于化学物质对其不同发育阶段的间接和亚致死效应的深入研究还不够充分。在本研究中，评估了一些杀虫剂对其卵的影响。通过对其卵缺陷的形态学观察，证实了灭幼脲、阿维菌素、氯虫苯甲酰胺和高效氯氟氰菊酯的杀卵活性。此外，我们从其卵中鉴定了昆虫中的四种重要蜕皮激素受体蛋白[即两种异构体蜕皮激素受体（EcR：CsEcRA、CsEcRB）和两种异构体超气门蛋白（USP：USP1、USP2）]。CsEcRA、CsEcRB、USP1和USP2基因分别由1521、1614、1410和1236个碱基对的开放阅读框组成，分别编码506、527、469和413个氨基酸残基的蛋白质。此外，通过qRT-PCR评估了CsEcRA、CsEcRB和卵黄原蛋白受体（VgR）对杀虫剂的胚胎差异反应。在五个测试基因中，CsEcRA和CsEcRB对所有测试杀虫剂最为敏感，与未处理的对照昆虫相比，其表达的倍数变化降低了4.27-8.70倍。数据表明，这些杀虫化合物调节这些特定蛋白质的表达，这最终可能导致其卵的活力降低。我们在此首次提供了关于蜕皮激素受体基因及其在其卵中对杀虫剂的差异反应的分子阐释数据。连同我们之前关于杀虫剂对其成虫两个繁殖相关基因的亚致死效应的报告，CsEcRA和CsEcRB似乎是评估杀虫剂对其影响的合适分子参数。本研究例证了核受体转录测量作为杀虫剂杀卵影响生态毒理学评估的分子生物标志物的潜在效用。
