Amsterdam Institute for Life and Environment (A-LIFE), Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
Keygene N.V., Agro Business Park 90, Wageningen, 6708 PW, The Netherlands.
Environ Sci Pollut Res Int. 2023 Sep;30(42):95338-95347. doi: 10.1007/s11356-023-28940-9. Epub 2023 Aug 5.
Neonicotinoid insecticides are harmful to non-target soil invertebrates, which are crucial for sustainable agriculture. Gene expression biomarkers could provide economic and high-throughput metrics of neonicotinoid exposure and toxicity to non-target invertebrates. Thereby, biomarkers can help guide remediation efforts or policy enforcement. Gene expression of Glutathione S-Transferase 3 (GST3) has previously been proposed as a biomarker for the neonicotinoid imidacloprid in the soil ecotoxicological model species Folsomia candida (Collembola). However, it remains unclear how reliably gene expression of neonicotinoid biomarkers, such as GST3, can indicate the exposure to the broader neonicotinoid family under putative GST enzymatic inhibition. In this work, we exposed springtails to two neonicotinoids, thiacloprid and imidacloprid, alongside diethyl maleate (DEM), a known GST metabolic inhibitor that imposes oxidative stress. First, we determined the influence of DEM on neonicotinoid toxicity to springtail fecundity. Second, we surveyed the gene expression of four biomarkers, including GST3, under mutual exposure to neonicotinoids and DEM. We observed no effect of DEM on springtail fecundity. Moreover, the expression of GST3 was only influenced by DEM under mutual exposure with thiacloprid but not with imidacloprid. The results indicate that GST3 is not a robust indicator of neonicotinoid exposure and that probable GST enzymatic inhibition mediates the toxicity of imidacloprid and thiacloprid differentially. Future research should investigate biomarker reliability under shifting metabolic conditions such as provided by DEM exposure.
新烟碱类杀虫剂对非靶标土壤无脊椎动物有害，而这些无脊椎动物对可持续农业至关重要。基因表达生物标志物可以提供新烟碱类暴露和对非靶标无脊椎动物毒性的经济高效和高通量指标。因此，生物标志物可以帮助指导修复工作或政策执行。先前已经提出谷胱甘肽 S-转移酶 3 (GST3)的基因表达作为土壤生态毒理学模型物种 Folsomia candida（弹尾目）中新烟碱类杀虫剂吡虫啉的生物标志物。然而，尚不清楚 GST 酶抑制作用下，新烟碱类生物标志物（如 GST3）的基因表达如何可靠地指示更广泛的新烟碱类家族的暴露。在这项工作中，我们将跳虫暴露于两种新烟碱类杀虫剂噻虫嗪和吡虫啉以及已知会引起 GST 代谢抑制和氧化应激的顺丁烯二酸二乙酯 (DEM)中。首先，我们确定了 DEM 对跳虫生殖力的新烟碱类毒性的影响。其次，我们在新烟碱类和 DEM 共同暴露的情况下调查了包括 GST3 在内的四个生物标志物的基因表达。我们没有观察到 DEM 对跳虫生殖力的影响。此外，只有在与噻虫嗪共同暴露时，GST3 的表达才受到 DEM 的影响，而与吡虫啉共同暴露时则不受影响。结果表明，GST3 不是新烟碱类暴露的可靠指标，并且 GST 酶的可能抑制作用对噻虫嗪和吡虫啉的毒性有不同的影响。未来的研究应在提供 DEM 暴露等代谢变化的情况下调查生物标志物的可靠性。
