Fig. 5.
Comparison of photosystem II quantum efficiency (Fv/Fm, a, b) and efficiency of primary quinone acceptor (QA) reoxidation in 0.65 ms (Fr1/Fv, c, d), and 120 ms (Fr2/Fv, e, f) relaxation phases in dark-adapted state acquired by light-induced fluorescence transient (LIFT) and double-modulated FL3000 fluorometer. Measurements were carried out on isolated spinach thylakoids and BBY particles. Thylakoid samples (10 µg chlorophyll/mL) were either untreated or treated with 5 µΜ 3−(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or 0.66 µM 2,5-dibromo-5-methyl-6-isopropyl-benzoquinone (DBMIB), resulting in different chlorophyll fluorescence relaxations as shown in Fig. 4. Black diamonds show mean values and error bars indicate the 95% confidence intervals. Individual data points are depicted by a grey point (n = 5, except DCMU FL3000 and DBMIB FL3000 n = 3). Means labeled with different letters differ significantly from each other according to Tukey’s multiple comparisons of means