Figure 4.

NADPH-dependent activity of chloroplast glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in diatoms (a–e). All panels show activity measurements of diatom crude extracts from cultures grown at low CO₂ (L-CO₂; 400 ppm, dark grey bars) or high CO₂ (H-CO₂; 20,000 ppm, light grey and dashed bars), as specified in panel (a), and without any treatment (none) or treated with either 0.2 mM NADPH or 5 mM DTT, or both prior to assay. Average and error bars (SD) are represented (n = 3). * p ≤ 0.05 and ns, not significant.