Fig. 2. Fluorescence emission (A–D), oxygen consumption and evolution (E–H) in C. reinhardtii wild-type (A and E), stt7 (B and F), bf4 (C and G) and A-AUU (D and H) cells during state transition. Cells were incubated in the dark. At 3 min intervals, a saturating light pulse was given to measure Fm. Fo corresponds to the lower trace in (A)–(D). The upward arrow indicates the switch on of the actinic light at time 0. Note that fluorescence emission was multiplied by a factor of 4 in (C).