Host: The Japanese Society of Plant Physiologists
Pages 0108
State transition is a mechanism that supports plant survival under various light conditions. Peripheral light-harvesting antennas of PSII (LHCIIs) reversibly migrate between PSII and PSI during state transitions. Recently, we revealed that three LHCIIs are associated with PSI, forming a PSI-LHCI/II supercomplex, in state 2. Notably, CP29 might act as a linker between PSI and major LHCIIs. In this study, we generated CP29-RNAi mutants (b4i) to investigate the specific role of CP29 during state transitions in Chlamydomonas reinhardtii. Sucrose density gradient ultracentrifugation of thylakoids from b4i-8 cells under state 2-promoting conditions revealed that there was no PSI-LHCI/II supercomplex in this mutant. Contrarily, results of both fluorescence and electron flow analyses indicated that b4i-8 could perform state transitions. We conclude that CP29 contributes to the formation of a PSI-LHCI/II supercomplex, but it is not essential for state transitions.
