Figure 1.

Effect of O₂ and OAA on the lag of O₂ evolution upon starting low light intensity illumination of state 2, anaerobic C. reinhardtii cells. Light was turned on at the upward arrow and off at the downward arrow. O₂ was added where indicated by the rising trace, upon injection of H₂O₂ to the catalase-containing oxygen electrode cell. OAA was 2 mm and added O₂ was 20 μm. Chlorophyll was 150 μg mL⁻¹ and light intensity was 54 μmol m⁻² s⁻¹ Other conditions as in Table I. C, Control. The lag time is defined as the intercept of the straight line drawn from the steady-state O₂ evolution trace with the straight line on the time scale, starting at the beginning of illumination (see also Finazzi et al., 1999).