Figure 7.
Time course of chlorophyll a fluorescence measured with P. cruentum (A) and C. caldarium (B). Samples without any addition (control) or in the presence (where indicated) of 10 μm 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or 1% glutaraldehyde are presented. Data are normalized to the maximal fluorescence obtained in the dark (Fm) before the fluorescence time course was recorded. Several saturation pulses were applied to obtain maximum fluorescence in the light (Fm′). The characteristic slow fluorescence rise (S-M rise) reflecting the state 2-to-state 1 transition is marked. For fluorescence excitation, orange diodes (λe = 590 nm, half-width Δλ = ±20 nm) were used. r.u., Relative units.