Abstract
We examined the effect of lack of Psb28 on photosynthetic machinery using a psb28 disruptant of Synechocystis sp. PCC 6803 under high temperature stress conditions. The mutant cells showed normal growth under low-light and high-light conditions at 30oC. However, the growth of mutant cells was retarded compared to wild-type cells under high-light conditions when the growth temperature was changed to higher temperatures above 38oC. Results obtained by experiments on photoinhibition of photosynthesis showed that photosynthetic machinery in the psb28 disruptant is more susceptible to photoinhibition at 40oC than that in the wild-type cells. These results suggest that Psb28 is involved in the repair cycle of photosynthetic machinery at higher temperatures.
