Fig. 2

Heatmap displays the fold change in the expression of proteins related to carbon metabolism processes. Proteins involved in the biophysical CCM, the C4-like pathway, the central carbon metabolism, the photorespiratory and the ornithine–urea cycle in the different concentrations of CO₂ cultivated P. tricornutum. Variations of protein abundances are indicated by fold change as HC/NC(H/N) and LC/NC(L/N). Detailed information about these differently expressed proteins are listed as an additional excel sheet (see Additional file 1: Table S1). White, filling in heatmap represent proteins that are not detected in NC, and little grey represent proteins that are not detected in LC, while deep grey represents proteins that are not detected in HC. Additionally, little blue represents proteins that are not detected in both LC and NC conditions, and deep blue represents proteins that are not detected in both HC and NC conditions. * Statistically significant (P < 0.05); ** statistically significant (P < 0.01). NC: normal CO₂; LC: low CO₂; HC: high CO₂