Abstract
State transition is a mechanism that redistributes excitation energy between PSI and PSII. When an excess energy is accumulated in PSII, LHCII is detached from PSII and reassociate with PSI, resulting in the increased excitation energy populates on PSI. Recently, we reported three monomeric LHCIIs (CP29, CP26 and LHCII-typeII) act as linkers between trimeric LHCII and PSI in State 2. In this study, we generated a RNAi mutant of CP29 (b41) to investigate on a specific role of CP29 in state transitiosn in Chlamydomonas reinhardtii. RT-PCR and western blot analysis indicated that LHCB4 mRNA level and the amount of CP29 in the b41 strain decreased to about one-fifth of that of wild type. The b41 strain did not grow under high light, indicating that the down-regulation of CP29 caused reduction of the ability of photoprotection. Additional results from physiological and biochemical studies on the b41 mutant will be presented.
