[en] Past activities of 2 smelters (Metaleurop Nord and Nyrstar) led to the accumulation of high amounts of Metal Trace Elements (TEs) in top soils of the Noyelles-Godault/Auby area, Northern France. Earthworms were exposed to polluted soils collected in this area to study and better understand the physiological changes, the mechanisms of acclimation, and detoxification resulting from TE exposure. Previously we have cloned and transcriptionally characterized potential biomarkers from immune cells of the ecotoxicologically important earthworm species Eisenia fetida exposed in vivo to TE-spiked standard soils. In the present study, analysis of expression kinetics of four candidate indicator genes (Cadmium-metallothionein, coactosin like protein, phytochelatin synthase and lysenin) was performed in E. fetida after microcosm exposures to natural soils exhibiting an environmental cadmium (Cd) gradient in a kinetic manner. TE body burdens were also measured. This microcosm study provided insights into: (1) the ability of the 4 tested genes to serve as expression biomarkers, (2) detoxification processes through the expression analysis of selected genes, and (3) influence of land uses on the response of potential biomarkers (gene expression or TE uptake). - Highlights: → Expression biomarkers in animals exposed to Cadmium-contaminated field soils. → Expression kinetics to test the ability of genes to serve as expression biomarkers. → Study of detoxification processes through the expression analysis of selected genes.

[en] This publication proposes a synthesis of results obtained within a multi-disciplinary research programme, Phytener, performed between 2009 and 2013. This programme notably considered the case of ancient mining sites and of the associated soil contaminations (by cadmium, lead or zinc), and the study of the use of phyto-technologies for a better management of highly contaminated agricultural spaces. These studies addressed management modes based on phyto-remediation (assisted or not) of cadmium, lead and zinc, with the implication of two biomass production sectors: wood (with the following species: Robinia pseudoacacia, Alnus glutinosa, Quercus ilex and Acer pseudoplatanus) and an herbaceous vegetation (Miscanthus x giganteus). The objective was then to assess the ecologic viability of the proposed management modes, to contribute to a sustainable redevelopment of agriculture, and to give back an economic interest to disqualified agricultural soils while meeting environmental, economic and social demands. Thus, the authors present the experimental approach and discuss the obtained results