Dark-induced reduction of the plastoquinone pool in zooxanthellae of scleractinian corals and implications for measurements of chlorophyll a fluorescence

摘要: Fluorometric measurements of maximum quantum yield (F v /F m ) and fast induction curves (FICs) require coral samples to be dark-adapted (DA). Pathways causing dark-reduction the plastoquinone (PQ) pool are shown here active in corals. Early morning sunlight far-red light successfully increased F lowered O J steps FICs corals that were darkened overnight. The thick-tissued massive coral, Cyphastrea serailia, was more prone reduction PQ pool, with significant reductions occurring after 10 min DA, elevated within 200 s following a flash. In thinner-tissued branching species, Pocillopora damicornis Acropora nobilis, elevation step also occurred but drop only manifested 30 min. Pre-exposure is an effective simple procedure ensure determination true Photosystem II (PSII) accurate which fully oxidised inter-system electron transport chain open PSII reaction centres.