The proposed project aims to assess the relationship between toxic metal bioavailability and expression of genes in two representative aquatic primary producers: a rooted macrophyte and a green microalgae, representing the aquatic plants and the phytoplankton typically found in the benthic environment and the water column.
Bioavailability of Cu and two speciation of Hg (inorganic HgCl2 and organic CH3HgCl) will be compared to transcriptome modifications analyzed by RNAseq as well as other endpoints including growth and photosynthesis in each organism. Bioavailability will be determined by measurement of the adsorbed and internalized metal concentrations at different exposure times. The specificity of the gene response to each toxicant and the response to their mixtures will be assessed. Genes identified in both organisms in similar conditions will be compared to determine how similar are primary producers’ response to heavy metals.