Figure 7.

Schematic Diagram of Chloroplast CBSX Function.

Under various oxidative stress conditions, CBSX1 is overexpressed and forms a functional homodimer, which then activates Trxs in the FTS. These stresses result in changes in the concentration of various adenosine-containing ligands, which are sensed by CBSX1 in the chloroplast. The CBSX1 functional homodimer is augmented by binding to a specific adenosine-containing ligand, resulting in an enhancement of the activation of all Trxs in the FTS. As a result, the cell maintains homeostasis through regulation of the Calvin cycle and H₂O₂ levels. Fd, ferredoxin; FNR, ferredoxin-NADP⁺ reductase; ox, oxidized; PC, plastocyanin; PQ, plastoquinone; PSI, photosystem I; PSII, photosystem II; red, reduced.