FIG. 4.

Effect of GA, KCN, and DMBQ on net proton movements involving WT (A to C and G to I) and coxAB (D to F) cells of Synechocystis. The light was switched on (arrow down) and off (arrow up). The cells were suspended in 0.2 mM TES-KOH buffer (pH 8.0) containing 15 mM NaCl at a chlorophyll concentration of 14 μg/ml. GA (final concentration, 20 mM) (B, C, E, and F) and KCN (5 mM) (H and I) were added prior to illumination and DMBQ (1 mM) (C, F, and H) was added in the dark to the cell suspensions after the profiles in the presence of the inhibitors were obtained.