Figure 7.

Electron donation to PQ in ruptured chloroplasts isolated from Arabidopsis leaves. Increase in chlorophyll fluorescence by the addition of NADPH (250 µm) and Fd (5 µm) under weak illumination (1.0 mmol photons m⁻² s⁻¹) was recorded in ruptured chloroplasts (1.5 mg chlorophyll mL⁻¹) from wild-type (WT) and mutant (pgr5 and ndho-1) leaves. The maximum PSII fluorescence in the dark-adapted state (Fm) level was recorded following the application of a saturating flash (SF). The maximum photochemical efficiency of PSII in the dark-adapted state values from the different samples were from 0.7 to 0.8. A, Typical trace of a chlorophyll fluorescence change in chloroplasts from wild-type leaves. B, Magnified traces from the boxed area in A obtained using chloroplasts from different mutants incubated with AA (5 mm), TRX E. coli (200 mm), or TRXm4 (200 mm). [See online article for color version of this figure.]