School of Environmental Science and Engineering, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China.
School of Life Sciences, Jiaying University, Meizhou 514015, China.
Sci Total Environ. 2023 Apr 15;869:161884. doi: 10.1016/j.scitotenv.2023.161884. Epub 2023 Jan 28.
Neonicotinoid pesticides are the most widely used insecticides worldwide and have become a global environmental issue. Previous studies have shown that imidacloprid, the most used neonicotinoid, can negatively affect a wide range of organisms, including non-target insects, fish, invertebrates, and mammals. Imidacloprid can also accumulate and persist in soils, posing threats to the terrestrial ecosystem. However, we know little about one ecologically important group of organisms, the single-celled soil protists. In this study, we used a soil amoeba, Dictyostelium discoideum, to test whether and how imidacloprid affects the growth and development of soil amoebae. We provide the first empirical evidence that environmental concentrations of imidacloprid negatively impact the fitness and development of soil amoebae. In addition, the adverse effects did not show a dose-response relationship with increased imidacloprid concentrations, where no significant difference was observed among the treatment groups. Further transcriptome analyses showed that imidacloprid affected amoeba's key DEGs related to phagocytosis, cell division, morphogenesis, and cytochrome P450. Moreover, soil amoebae show both conserved and novel transcriptional responses to imidacloprid. In conclusion, this study has expanded the non-target list of imidacloprid from animals and plants to single-celled protists, and we believe the impact of neonicotinoid pesticides on the microbiome is significantly underestimated and deserves more studies.
新烟碱类杀虫剂是世界上使用最广泛的杀虫剂，已成为全球性的环境问题。先前的研究表明，最常用的新烟碱类杀虫剂之一——吡虫啉，会对包括非靶标昆虫、鱼类、无脊椎动物和哺乳动物在内的广泛生物产生负面影响。吡虫啉还会在土壤中积累和持久存在，对陆地生态系统构成威胁。然而，我们对一个生态上重要的生物群体——单细胞土壤原生动物知之甚少。在这项研究中，我们使用土壤变形虫——Dictyostelium discoideum，来测试吡虫啉是否以及如何影响土壤变形虫的生长和发育。我们提供了首个经验证据，表明环境浓度的吡虫啉会对土壤变形虫的适应性和发育产生负面影响。此外，这种不利影响与吡虫啉浓度的增加没有表现出剂量-反应关系，在各处理组之间未观察到显著差异。进一步的转录组分析表明，吡虫啉影响了变形虫与吞噬作用、细胞分裂、形态发生和细胞色素 P450 相关的关键 DEGs。此外，土壤变形虫对吡虫啉表现出保守和新颖的转录反应。总之，本研究将吡虫啉的非靶标清单从动物和植物扩展到单细胞原生动物，我们认为新烟碱类杀虫剂对微生物组的影响被大大低估了，值得进一步研究。
