Fig. 6.

Model of PSI-MC dynamics. a After overnight darkness PSI-MCs in the stromal lamellae are associated with a portion of the mobile LHC pool. b At the onset of daylight, PSI-MCs associate with PSII at the grana margins, forming the band 4 heterocomplex. c In low light, PSI-MCs are dismantled and the LHC associated with the PSI-MCs becomes part of the PSII antenna in the grana. d In high light, LHC remains associated with PSI-MCs, leaving PSII cores exposed at the grana margins and facilitating PSII turnover. e Increasing expression of PsaL/H with age allows more of the LHC pool to associate with PSI in PSI-MCs, releasing PSII to be degraded. This process is accelerated by induction of PSI-MC formation in high light