Fig. 4.

slac1-1 and slac1-3 mutants impair 1 mM malate activation of S-type anion channel currents in Arabidopsis thaliana guard cells. (a) Typical whole-cell recordings of S-type anion channel currents in guard cell protoplasts of wild type (WT), slac1-1 and slac1-3 mutant plants with 1 mM malate and 2 μM free Ca²⁺ in the pipette solution that dialyzes the cytosol. (b) Steady-state current-voltage relationships recorded as in (a). The number of guard cells was n = 5–7. Data are mean ± SE (P < 0.01 for slac1-1 + 1 mM malate vs WT + 1 mM malate; P < 0.01 for slac1-3 + 1 mM malate vs WT + 1 mM malate at −145 mV).