Figure 1. Scheme of chloroplast redox regulation in the stroma.
A schematic representation of two reduction pathways (A), FNR/NTRC and FTR/Trx under different light availability, and (B) oxidation pathway under dark is shown. (A) Under high light intensity, the FTR regulatory system dominantly reduces thiol-regulated target enzymes. Under limited light availability, the NTRC system mainly functions. (B) Under dark, 2CP mediates oxidizing the target enzymes. More details can be found in Section 2. The arrows indicate the flow of reducing equivalents, with blue representing reduction and pink representing oxidation.
Abbreviations: ETC, Electron transport chain; FNR, ferredoxin-NADP+ reductase; FTR, ferredoxin-thioredoxin reductase; NTRC, NADPH-dependent thioredoxin reductase C;
2CP, 2 Cys-peroxiredoxin