School of Life Sciences, Jinggangshan University, Ji'an, 343009, China.
Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China.
Ecotoxicol Environ Saf. 2021 Jan 15;208:111581. doi: 10.1016/j.ecoenv.2020.111581. Epub 2020 Nov 5.
Lead (Pb) stress affects hormone-mediated responses (e.g., reproduction) in insects. In this study, the effects of Pb stress (12.5-50 mg Pb/kg in larval artificial diets) on the reproduction of the common cutworm Spodoptera litura (Lepidoptera: Noctuidae) were investigated after 7 generations. The results showed that Pb stress did not reduce the longevity of adult females, but 50 mg Pb/kg significantly reduced the longevity of adult males, regardless of the generation. After 50 mg Pb/kg stress for one or 7 generations, the peak time of egg-laying was delayed, and egg production and hatchability were decreased significantly. The vitellin content in eggs was significantly inhibited by Pb stress. The S. litura vitellogenin (Vg) gene promoter was cloned and analyzed. Multiple putative transcription factors were predicted for the 2321 bp Vg promoter region, including the TATA box, GATA, basic helix-loop-helix (bHLH) transcription factor, Broad-Complex (BR-C) binding sites, etc. The fragment from -2222 to -211 bp of the Vg promoter was the activation domain for Vg, whereas the region from -211 to -55 bp repressed the activity of the Vg promoter. The construct promoter (-782/+76) in Trichoplusia ni (Hi5) cells significantly improved Vg expression, which was not affected by Pb stress (1 or 10 mg/ml). Therefore, Pb stress significantly inhibited the reproduction of S. litura but not by regulating the Vg promoter.
铅（Pb）胁迫会影响昆虫的激素介导反应（例如繁殖）。在这项研究中，研究了 Pb 胁迫（幼虫人工饲料中的 12.5-50mg Pb/kg）对 7 代后斜纹夜蛾（鳞翅目：夜蛾科）繁殖的影响。结果表明，Pb 胁迫并未降低雌成虫的寿命，但 50mg Pb/kg 显著降低了雄成虫的寿命，而与代际无关。在 50mg Pb/kg 应激 1 代或 7 代后，产卵高峰期延迟，产卵量和孵化率显著降低。卵中的卵黄蛋白含量受到 Pb 胁迫的显著抑制。克隆并分析了斜纹夜蛾卵黄原蛋白（Vg）基因启动子。预测了 2321bp Vg 启动子区域的多个潜在转录因子，包括 TATA 盒、GATA、碱性螺旋-环-螺旋（bHLH）转录因子、宽复合物（BR-C）结合位点等。Vg 启动子从-2222 到-211bp 的片段是 Vg 的激活区，而从-211 到-55bp 的区域则抑制了 Vg 启动子的活性。转染到 Hi5 细胞中的构建启动子（-782/+76）显著提高了 Vg 的表达，而 Pb 胁迫（1 或 10mg/ml）对其没有影响。因此，Pb 胁迫显著抑制了斜纹夜蛾的繁殖，但不是通过调节 Vg 启动子。
