Eisenia andrei exposed to different 2-phenylethyl isothiocyanate concentrations in soil

ABSTRACT: Background: Earthworms are essential for a healthy soil ecosystem, performing key functions such as bioturbation. The soil ecosystem can be challenged by natural toxins such as isothiocyanates (ITC), secondary metabolites produced by many commercial crops. This study investigated the effects of the natural toxin, 2-phenylethyl isothiocyanate on the earthworm Eisenia andrei using an ecotoxicogenomics approach that combined standardised ecotoxicological testing with gene expression analyses. Results and discussion: Exposure to 2-Phenylethyl ITC reduced both survival and reproduction of E. andrei in a dose-dependent manner, with an EC50 (reproduction) value of 556 nmol/g soil. Cross-species comparative genomic hybridisation validated the applicability of an existing 4x44k E. fetida microarray to E. andrei. Gene expression profiles revealed the importance of metallothionein (mt) as an early warning signal when E. andrei is exposed to low concentrations of 2-phenylethyl ITC. Allignment of these mt genes with the mt-2 gene of Lumbricus rubellus showed that there must at least have 2 mt genes in the Eisenia sp. genome. At high exposure concentrations of 2-phenylethyl ITC gene expression was mainly affected by inhibiting chitinase activities, inducing an oxidative stress response, and stimulating energy metabolism. KEGG pathway analysis, furthermore, implied that the high concentration may cause impaired light sensitivity, angiogenesis (e.g. wound healing), olfactory perception (olfaction), learning and memory. Conclusions: Increased levels of isothiocyanates may be found in the field in the near future. Risks of such compounds should be carefully investigated before allowing them to enter the soil on a large scale. This is the first study to investigate the effects of an isothiocyanate on an earthworm both on the ecotoxicological and genomic level.

ORGANISM(S): Eisenia andrei Eisenia fetida

PROVIDER: GSE43600 | GEO | 2013/08/11

SECONDARY ACCESSION(S): PRJNA187085

REPOSITORIES: GEO