Gene expression overview of S. marinoi with aging, nutrient starvation and CO2 enrichment. Summary of expression level results of the studied gene categories (Heat shock proteins, Aldehyde dehydrogenases, Glutathione-related enzymes, and other antioxidants) in different tested conditions: Aging (a), Nutrient starvation (Silicic acid starvation/depletion, b), CO2 bubbling (for 4 h or continuously, c). Arrows indicate up- or down-regulation of selected genes. N/S indicates that non-significant gene expression changes were observed. Gene abbreviations used are: Heat shock proteins (HSP), luminal binding protein (LBP), aldehyde dehydrogenases (ALDH), succinate dehydrogenase (SSD), betaine ALDH (BALDH), glutathione synthase (GSH-S), glutathione peroxidase (GPX), glutathione reductase (GR), glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), ascorbate peroxidase (AP), tocopherol cyclase (TOCC), glycolate oxidase (GOX), ATP-binding cassette transporter (ABC).