Abstract
Photosystem II (PSII) is known to suffer from oxidative damage even under moderate light intensity and be actively repaired to sustain its activity. This mechanism is called PSII repair cycle, and factors involved in the cycle and how it proceeds are studied by genetic and biochemical approaches. However, it is not clear how PSII extrinsic subunits in thylakoid lumen called oxygen evolving proteins (OEC proteins) are involved in this process. In previous report, we showed that suppression of PsbP, the OEC protein specifically found in land plants and some green algae, leads to the decrease of accumulation of PSII-LHCII super-complex in tobacco leaves. In this study, we further analyzed super-complex organization on thylakoid membranes by Blue-Native PAGE and sucrose density gradient centrifugation, and examined the effect of PsbP knock-down to clarify the function of PsbP in PSII repair cycle.
