Figure 8.

Model of the photoprotective function of 2-Cys PRX and tAPX. The WWC and other alternative electron flows (AEFs) are proposed to prevent overreduction of the linear electron transport chain (LET) and protect the photosystems from oxidative damage. Under HL conditions, 2CPs are essential for maintaining a WWC and more important than plastid APX involved in the classical WWC for protection of the photosystems. 2-Cys PRX and tAPX synergistically inhibit activation of redox-responsive genes and prevent overaccumulation of H₂O₂ as well as photooxidative damage under HL conditions. FNR, Fd NADP oxidoreductase; SOD, superoxide dismutase.