Project description:To understand molecular mechanisms of the joint effects of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), both widely used ordnance compounds, we constructed a microarray consisting of 4,032 cDNA isolated from the earthworm Eisenia fetida using the suppressive subtractive hybridization technique. Worms were exposed to TNT-, RDX-, or TNT+RDX-spiked soil for 28 days (TNT 50 mg/kg, RDX 30 mg/kg). Keywords: Combined toxicity of TNT and RDX to earthworm (Eisenia fetida)
Project description:To understand molecular mechanisms of the chronic, sublethal toxicity of 2,4,6-trinitrotoluene (TNT), a widely used ordnance compound of public concerns, we constructed a microarray consisting of 4,032 cDNA isolated from the earthworm Eisenia fetida using the suppressive subtractive hybridization technique. Worms were exposed to a gradient of TNT-spiked soil for 28 days. Based on the reproduction response to TNT, four treatments, i.e., control, 7, 35 and 139 ppm, were selected for gene expression studies. Keywords: Sublethal toxicity of TNT (dose-response) to earthworm (Eisenia fetida)
Project description:To understand molecular mechanisms of the joint effects of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), both widely used ordnance compounds, we constructed a microarray consisting of 4,032 cDNA isolated from the earthworm Eisenia fetida using the suppressive subtractive hybridization technique. Worms were exposed to TNT-, RDX-, or TNT+RDX-spiked soil for 28 days (TNT 50 mg/kg, RDX 30 mg/kg). Keywords: Combined toxicity of TNT and RDX to earthworm (Eisenia fetida) We analyzed 40 arrays for 4 treatments (control, TNT 50ppm, RDX 30ppm, TNT 50ppm + RDX 30ppm) with 5 biological replicates per treatment using an interwoven loop design.
Project description:Analysis of microbial community composition in arctic tundra and boreal forest soils using serial analysis of ribosomal sequence tags (SARST). Keywords: other
Project description:Soil microbial community is a complex blackbox that requires a multi-conceptual approach (Hultman et al., 2015; Bastida et al., 2016). Most methods focus on evaluating total microbial community and fail to determine its active fraction (Blagodatskaya & Kuzyakov 2013). This issue has ecological consequences since the behavior of the active community is more important (or even essential) and can be different to that of the total community. The sensitivity of the active microbial community can be considered as a biological mechanism that regulates the functional responses of soil against direct (i.e. forest management) and indirect (i.e. climate change) human-induced alterations. Indeed, it has been highglihted that the diversity of the active community (analyzed by metaproteomics) is more connected to soil functionality than the that of the total community (analyzed by 16S rRNA gene and ITS sequencing) (Bastida et al., 2016). Recently, the increasing application of soil metaproteomics is providing unprecedented, in-depth characterisation of the composition and functionality of active microbial communities and overall, allowing deeper insights into terrestrial microbial ecology (Chourey et al., 2012; Bastida et al., 2015, 2016; Keiblinger et al., 2016). Here, we predict the responsiveness of the soil microbial community to forest management in a climate change scenario. Particularly, we aim: i) to evaluate the impacts of 6-years of induced drought on the diversity, biomass and activity of the microbial community in a semiarid forest ecocosystem; and ii) to discriminate if forest management (thinning) influences the resistance of the microbial community against induced drought. Furthermore, we aim to ascertain if the functional diversity of each phylum is a trait that can be used to predict changes in microbial abundance and ecosystem functioning.
Project description: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.
Project description: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. Three-exposure experiment; Acetone control vs.EC10 vs.EC50 exposed animals. Biological replicates: 4 replicates for each exposure. Technical replicates: 2 replicates for each exposure
Project description:To study long-term elevated CO2 and enriched N deposition interactive effects on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. There exist antagonistic CO2×N interactions on microbial functional genes associated with C, N, P S cycling processes. More strong antagonistic CO2×N interactions are observed on C degradation genes than other genes. Remarkably antagonistic CO2×N interactions on soil microbial communities could enhance soil C accumulation.