Abstract
It has been reported two fluorescence emission bands at 685 nm(F685) and 695 nm(F695) in photosystem II(PSII) at 77 K, emitted from chlorophyll a in the core antenna CP43 and CP47, respectively. This study, we measured the fluorescence dynamics of a Arabidopsis thaliana leaf in the picosecond time region at 5 K, 40 K and 77 K. We found a new band at 687 nm(F687). With increasing temperature, the decay rate of F687 became faster so that in a later time region it could not be distinguished from F695 because of the overlap with F695. We also observed F687 in the spinach PSII and Synechocystis sp. PCC 6803 at 5-77 K. Each bands in cyanobacteria decay faster than those of higher plants. We will propose a model for the excitation-energy transfer dynamics in PSII, accounts for the rise and decay kinetics of the fluorescence bands.
