School of Forestry, Northeast Forestry University, Harbin, 150040, PR China; Key Laboratory of Sustainable Forest Ecosystem Management, Ministry of Education of PR China, Northeast Forestry University, Harbin, 150040, PR China.
Key Laboratory of State Forestry and Grassland Administration on Forest Pest Monitoring and Warning, General Station of Forest and Grassland Pest Management, National Forestry and Grassland Administration, Shenyang, 110034, PR China.
Environ Pollut. 2020 Nov;266(Pt 3):115173. doi: 10.1016/j.envpol.2020.115173. Epub 2020 Jul 5.
Cadmium, a common environmental contaminant in both terrestrial and aquatic ecosystems, presented a serious hazard to growth and development of phytophagous insects. For better understanding the toxicology of Cd exposure on phytophagous insects, the physiological and molecular mechanisms underlying the energy metabolism disorder in midgut tissue of gypsy moth larvae fed on Cd-amended artificial diets (3.248 or 44.473 mg Cd/kg fresh food) were investigated. Our results showed that compared with control, Cd exposure at both two levels triggered detriment effects on growth indexes, and with the increase of exposure concentrations, the adverse effects were significantly exacerbated. Larval growth and nutritional indexes (except approximate digestibility) showed a strong positive correlation, indicating that growth retardation in the gypsy moth larvae under Cd stress was tightly related to the food utilization. The key genes at mRNA level in glycolysis/gluconeogenesis, citrate cycle pathway and starch/sucrose metabolism pathway also presented a significant and positive correlation with growth indexes, once again demonstrating that energy metabolism was the key factor that controls the growth and development of the gypsy moth larvae under Cd stress. Antioxidant system collapse and oxidative damage, a chief cause of histopathological alterations in midgut tissue, consist of the physiological basis of energy metabolism disorder in Cd-treated gypsy moth larvae. Together, these results suggest that histopathological alterations or oxidative damage of tissue structure significant disturbed physiological functions of midgut tissue in gypsy moth larvae exposed to Cd stress, as reflected via food utilization or energy metabolism disorder, and eventually resulted in larval growth retardation.
镉是陆地和水生生态系统中常见的环境污染物，对植食性昆虫的生长和发育构成严重威胁。为了更好地了解 Cd 暴露对植食性昆虫的毒理学，研究了喂食添加 Cd 的人工饲料（3.248 或 44.473 mg Cd/kg 新鲜食物）的舞毒蛾幼虫中肠组织能量代谢紊乱的生理和分子机制。我们的结果表明，与对照相比，两种水平的 Cd 暴露都对生长指标产生了不利影响，随着暴露浓度的增加，不利影响显著加剧。幼虫生长和营养指标（近似消化率除外）呈强正相关，表明 Cd 胁迫下舞毒蛾幼虫的生长迟缓与食物利用密切相关。糖酵解/糖异生、柠檬酸循环途径和淀粉/蔗糖代谢途径中关键基因在 mRNA 水平上也与生长指标呈显著正相关，再次表明能量代谢是控制 Cd 胁迫下舞毒蛾幼虫生长发育的关键因素。抗氧化系统崩溃和氧化损伤是中肠组织组织学改变的主要原因，构成了 Cd 处理舞毒蛾幼虫能量代谢紊乱的生理基础。总之，这些结果表明，Cd 胁迫下舞毒蛾幼虫中肠组织的组织结构的组织学改变或氧化损伤显著干扰了中肠组织的生理功能，如食物利用或能量代谢紊乱，最终导致幼虫生长迟缓。
