Figure 4.

Chloride contents and analysis of Cl⁻ fluxes at the plasma membrane and tonoplast resolved over the diurnal Reference Cycle as described in Figure 1 (12 h light:12 h dark, indicated by bars above). Shown are total cytosolic and vacuolar [Cl⁻] (A), the net flux of Cl⁻ across the plasma membrane and tonoplast (B), the flux of Cl⁻ through the Cl⁻-permeable transporters at the plasma membrane, comprising the SLAC and R- (ALMT-)type anion channels and H⁺-Cl⁻ symporter (C), and the flux of Cl⁻ through the Cl⁻-permeable transporters at the tonoplast, comprising the VCL channel and CLC H⁺-Cl⁻ antiporter (D). Note the difference in scales between C and D. Note that positive flux is defined as movement of the ionic species (not the charge) out of the cytosol, either across the plasma membrane or the tonoplast.