Abstract
In the present study we investigated the effect of the Calvin cycle inhibition on photoinactivation of PSII. When Chlamydomonas reinhardtii (wild type) cells were exposed to light, glycolaldehyde (GA), which inhibits the Calvin cycle, stimulated the photoinactivation. The effect of GA on the photoinactivation was similar to that of chloramphenicol. The photoinactivation in a Rubisco missense mutant (10-6C) was faster than that in wild-type. However, it was not further accelerated by GA and chloramphenicol. After photoinactivation treatment, PSII activity in wild-type cells gradually recovered under low light. However, no significant recovery was observed when the Calvin cycle is inhibited. The inhibition of the Calvin cycle suppressed the synthesis of proteins, which are encoded in chloroplastic genome. These observations suggest that the level of photoinactivation is enhanced by the inhibition of the repair system when the Calvin cycle is inhibited by high temperature.
