Fig. 12.

Left hand panel. Variable fluorescence in aqueous suspension of Nannochloropsis upon 1 s SP (500 μmol photons m⁻²s⁻¹) in absence (blacks) and presence (reds) of 1 μM DCMU). The herbicide was added in strict darkness. Data are average of 12 experiments with three samples. Right hand panel: Same data in the 0 to 0.5 ms time range as in left hand panel, but plotted on a linear time scale. It shows the following properties: Fo in the presence of DCMU has increased to 1.25 with unaltered F _m ~ 3F _o. Initial rate of fluorescence increase at onset of SP is insensitive to DCMU (dashed lines in right hand panel). Initial fluorescence increase in the presence of DCMU is sigmoidal