Laboratory of Agrobiodiversity and Ecotoxicology, University of Sousse, Tunisia; Regional Research Centre in Horticulture and Organic Agriculture, Chott-Meriem, Sousse, Tunisia.
Laboratory of Agrobiodiversity and Ecotoxicology, University of Sousse, Tunisia; Regional Field Crops Research Center of Beja, IRESA, Tunisia.
Sci Total Environ. 2023 Aug 20;887:163950. doi: 10.1016/j.scitotenv.2023.163950. Epub 2023 May 8.
Heavy metal pollution is causing harmful consequences on soil fertility, and earthworms are frequently employed as test organisms to evaluate the ecotoxicity of polluted soils. In this study, Eisenia andrei was exposed for 7 and 14 days to polymetallic contaminated soils collected from an industrial zone in the south-eastern Tunisia. Earthworm growth, heavy metal accumulation, genotoxicity, cytotoxicity, biochemical and transcriptional responses were determined. Results revealed a higher accumulation of heavy metals in earthworms after 14 than 7 days of soil exposure, a reduction in lysosomal membrane stability (LMS), besides an increase in micronuclei frequency (MN). Moreover, earthworm oxidative status was affected in terms of increases in malondialdehyde (MDA) and metallothionein (MTs) content, and enhancement of catalase (CAT) and glutathione-S-transferase (GST) activities. An inhibition of acetylcholinesterase (AChE) activity was also observed in treated earthworms, whereas transcriptional data demonstrated an up-regulation of cat, gst, mt, p21 and topoisomerase genes. Overall, these findings support the use of earthworms as suitable bioindicator species for pollution monitoring and assessment, advance our understanding of the interaction between heavy metals and earthworms, and provide valuable information about the harmful impact of biota exposure to naturally contaminated soils.
重金属污染对土壤肥力造成了有害影响，而蚯蚓通常被用作测试生物来评估污染土壤的生态毒性。本研究采用东南突尼斯工业区采集的多金属污染土壤，对赤子爱胜蚓进行了 7 天和 14 天的暴露实验。测定了蚯蚓的生长、重金属积累、遗传毒性、细胞毒性、生化和转录响应。结果表明，土壤暴露 14 天后蚯蚓体内重金属积累量高于 7 天，溶酶体膜稳定性（LMS）降低，微核频率（MN）增加。此外，蚯蚓的氧化状态受到影响，表现为丙二醛（MDA）和金属硫蛋白（MTs）含量增加，过氧化氢酶（CAT）和谷胱甘肽-S-转移酶（GST）活性增强。处理后的蚯蚓乙酰胆碱酯酶（AChE）活性也受到抑制，而转录数据表明 cat、gst、mt、p21 和拓扑异构酶基因上调。总的来说，这些发现支持将蚯蚓用作污染监测和评估的合适生物指示剂物种，增进了我们对重金属与蚯蚓相互作用的理解，并提供了关于生物群暴露于自然污染土壤的有害影响的有价值信息。
