Analysis of the effects of BP-3 and BP-4 on the transcriptome of Chlamydomonas reinhardtii: An RNA-Seq approach

Abstract Benzophenones (BPs) are one of the most widely used UV-filters and previous flow cytometric studies have shown that these aquatic emerging pollutants alter physiology freshwater microalga Chlamydomonas reinhardtii . In order to obtain a more detailed study different cellular metabolic pathways affected, changes caused by BPs in transcriptome C. were investigated using RNA-Seq analysis after 24 h exposure. Each benzophenone at its corresponding 96 h-EC 50 value for growth provoked alterations gene expression this microalga, although BP-3-exposed cells showed higher number differentially expressed genes than exposed BP-4. GO enrichment analyses suggested both compounds affected same pathways. Transcripts encoding light-harvesting chlorophyll-binding proteins highly reduced. addition, an overexpression related amino acid catabolism was also detected, suggesting oxidize acids energy when photosynthesis damaged pollutants. Regarding oxidative damage contaminants, main antioxidant enzymes involved glutathione-associated metabolism upregulated. Moreover, sulphur could some relevance explain mechanism action BP-4 lower toxicity on microalgae, since sulfonic group is major structural difference between BPs. Obtained results suggest impaired UV-filters, leading microalgae via heterotrophic survive. Thus, occurrence sunscreens ecosystems trigger worrying reduction global CO 2 fixation.