Figure 4.
Lack of chlororespiration induces reversible overreduction of the photosynthetic apparatus in the periods of darkness. A, Fv/Fm of the wild type (WT) and the ptox2 mutant at the end of each dark period during the 30-min 0/340 μE m−2 s−1 intermittent-light treatment (black bar) and a 15-min 150 μE m−2 s−1 continuous-light recovery (gray bar). n = 4 ± sd. B and C, Relative concentrations of the reduced form of the QA quinone in the wild type and the ptox2 mutant after the first (B) and last (C) illumination of the 30-min intermittent-light treatment. n = 3 ± sd. D, ΦPSI in the wild type and the ptox2 mutant at the end of each dark period during the 30-min 0/340 μE m−2 s−1 intermittent-light treatment. n = 4 ± sd. The cells used in all experiments were grown in heterotrophic conditions.