Delayed fluorescence emitted from light harvesting complex II and photosystem II of higher plants in the 100 ns–5 μs time domain

摘要: This study presents the first report on delayed fluorescence (DF) emitted from spinach thylakoids, D1/D2/Cytb-559 preparations and solubilized light harvesting complex II (LHCII) in ns time domain after excitation with saturating laser flashes. The use of a new commercially available multichannel plate rapid gating permitted sufficient suppression detector distortions due to strong prompt fluorescence. following results were obtained: (a) dark-adapted DF amplitudes at 100 5 μs each flash train actinic pulses exhibit characteristic period four oscillations opposite sign: oscillate same manner as quantum yield fluorescence, whereas those resemble oscillation kinetics P680+ reduction samples an intact water oxidizing complex, (b) total emission range up few is estimated be <10−4 for (c) exhibits monophasic decay τ≈50 ns, (d) also observed isolated LHCII biphasic characterized by τ values 65 about 800 (e) contrast do not any pattern (f) all spectra different sample types are lowest excited singlet state chlorophyll a. implications these findings problems addressed future research briefly discussed.