Fig. 3.

In vivo measurement of NDH activity. After the actinic light illumination (ACT1; 85 μmol photons m^-2·s^-1), the transient increases in chlorophyll fluorescence were measured under dim light (Act2; 3 μmol m^-2·s^-1), recorded, and are shown in the enlarged boxes. This transient increase represents the reduction of the plastoquinone pool by the reducing equivalents accumulated during actinic illumination, confirmed by the experimental result that the transient increase disappeared when illuminated by far-red light after actinic illumination.