Project description:Lemna minor a small aquatic plant has been used extensively in ecotoxicolgical testing to elucidate substance-related effects to freshwater plants. They are free-floating freshwater macrophyte, very sensitive towards chemical exposure and easy to cultivate thus makes the plant suitable for laboratory testing. Here we present a rapid and reproducible data dependent proteomics approach for identifying growth related molecular signatures in lemna minor as an alternative to algae testing. For this, we have analyzed the proteome of lemna minor exposed to atorvastatin as a model substances for identifying growth related molecular perturbations. These fingerprints allow for a definition of potential biomarkers as tools in screening approaches and for integration in plant growth inhibition studies (OECD TG 221), for identifying suspect substances.
Project description:Lemna minor a small aquatic plant has been used extensively in ecotoxicolgical testing to elucidate substance-related effects to freshwater plants. They are free-floating freshwater macrophyte, very sensitive towards chemical exposure and easy to cultivate thus makes the plant suitable for laboratory testing. Here we present a rapid and reproducible data dependent proteomics approach for identifying growth related molecular signatures in lemna minor as an alternative to algae testing. For this, we have analyzed the proteome of lemna minor exposed to bentazon as a model substances for identifying growth related molecular perturbations. These fingerprints allow for a definition of potential biomarkers as tools in screening approaches and for integration in plant growth inhibition studies, for identifying suspect substances, such as in the Lemna sp. growth inhibition test (OECD TG 221).
Project description:Duckweeds are small, rapidly growing aquatic flowering plants. Due to their ability for biomass production at high rates they represent promising candidates for biofuel feedstocks. Duckweeds are also excellent model organisms because they can be maintained in well-defined liquid media, usually reproduce asexually, and because genomic resources are becoming increasingly available. To establish a framework for quantitative metabolic research in duckweeds we derived a central carbon metabolism network model of Lemna gibba based on its draft genome. Lemna gibba fronds were grown in a photomixotrophic mode in liquid media under continuous light with 13C-labeled glucose as a carbon source. Two different conditions (nitrate vs. glutamine as nitrogen source) were compared by quantification of growth kinetics, metabolite levels, metabolic flux and transcript abundance.
Project description:In this study, Lemna minor was used to investigate ecotoxic modes-of-action (MoA) at the gene expression level. For this purpose, mRNA sequencing was applied to plant RNA extracted from L. minor exposed to the herbicide bentazon in a shortened version of the OECD guideline test No. 221 (OECD TG 221). L. minor is commonly used as a non-target model organism to determine ecotoxicological effects of xenobiotics. As bentazon is one of the five most frequently detected pesticides in European groundwater, it is known for its environmental impact. Therefore, aquatic organisms, especially plants like L. minor, may be affected by its photosynthesis inhibition. The aim of our study was to determine a molecular fingerprint of the substance in order to identify potential biomarkers for its MoA. Therefore, we applied bioinformatics approaches to functionally annotate the previously unannotated reference genome of L. minor. Our functional annotation pipeline is in principle applicable to any organism with an available reference genome and thus greatly facilitates the identification of gene functions for poorly annotated organisms. The observed effects at the molecular level showed promising results for the development of OMICs as screening methods as well as for the identification of biomarkers for the toxicity of bentazon in L. minor.
Project description:In this study, Lemna minor was used to investigate ecotoxic modes-of-action (MoA) at the gene expression level. For this purpose, mRNA sequencing was applied to plant RNA extracted from L. minor exposed to the pharmaceutical atorvastatin in a shortened version of the OECD guideline test No. 221 (OECD TG 221). L. minor is commonly used as a non-target model organism to determine ecotoxicological effects of xenobiotics. Since atorvastatin (and statins in general) are frequently used pharmaceuticals, they can be found in the aquatic environment. In humans, they are used as cholesterol-lowering agents due to their hydroxymethylglutaryl-CoA reductase (HMGR) inhibitory effect. Analogously, in L. minor, atorvastatin can also inhibit the plant’s HMGR, which is involved in phytosterol synthesis. The aim of our study was to determine a molecular fingerprint of the substance in order to identify potential biomarkers for its MoA. Therefore, we applied bioinformatics approaches to functionally annotate the previously unannotated reference genome of L. minor. Our functional annotation pipeline is in principle applicable to any organism with an available reference genome and thus greatly facilitates the identification of gene functions for poorly annotated organisms. The observed effects at the molecular level showed promising results for the development of OMICs as screening methods as well as for the identification of biomarkers for the toxicity of atorvastatin in L. minor.
Project description:Testing for toxicity in a number of aquatic organisms is necessary for risk assessments of substances. Yet, aquatic larvae of the so-called EPT (Ephemeroptera, Plecoptera, Trichoptera) taxa are regularly exposed to several environmental contaminants and have been demonstrated to be extremely vulnerable to a variety of environmental pollutants. These results show that existing toxicity testing can result in an underestimating of the risk for EPT taxa and that more toxicity data using EPT taxonomic representatives are needed. Unfortunately, there is a dearth of standardized test techniques and scant published data, particularly for European EPT species. Our study's objective was to create a testing framework for a variety of endpoints in the mayfly Cloeon dipterum. Due to its high prevalence in local waterbodies and its brief lifecycle of a few weeks in the right environmental conditions, C. dipterum was selected as the test organism. To this end, two chronic toxicity tests with semi-static test design and two media renewal per week were performed. Small larvae in the stage L3 based on the wing pad development described by Cianciara (1976) were used in the tests. Four replicates per test concentration and control containing five individuals per replicate were installed. The emergence was determined daily on working days. The tests were conducted at a temperature of 20 °C (± 1 °C) and the illumination was < 1 µE m2s 1 with a light and dark rhythm of 16:8 h. The physico-chemical parameters pH, oxygen concentration, and oxygen saturation were measured using the multiparameter device WTW Multi 1970i at test start, throughout each media renewal, and at test end. Continuous temperature measurements were taken, and weekly lighting assessments were made. Fipronil was administered to C. dipterum larvae in the long-term exposure experiment at nominal concentrations ranging from 0.038 to 0.60 g/L. This test was conducted for 38 days until all larvae had emerged. In the short-term exposure experiment, C. dipterum larvae were exposed to Fipronil in nominal concentrations between 0.038 and 0.30 µg/L for a test duration of seven days. At test end, the larvae were sampled for transcriptome analysis.