Abstract
Phosphatidylglycerol (PG) is the only phospholipid in thylakoid membranes and its function for photosynthesis is great of interest. We previously isolated a pgsA mutant of Synechocystis sp. PCC 6803, defective in biosynthesis of PG. We have already demonstrated that PG plays an important role for the function of plastquinone QB in the photosystem II (PS II).
In this study, we have studied the function of PG in the formation of PS II complex. In the mutant, photoinhibition was easily induced after deprivation of PG and it was mainly caused by impairment of repair step of photosynthetic machinery. We further analyzed molecular background of this photoinhibition and demonstrated that dimerization of PS II complex was limited in the mutant under high light condition. These results suggest that PG plays an important role for maintenance of photosynthetic machinery through dimerization of PS II complex.
