Fig. 2: Impairments of blue light-dependent stomatal opening and H⁺ pumping in phosphodefective mutants of Thr-881 and Thr-948 of AHA1.

a Light-dependent changes in stomatal conductance in the intact leaves. Leaves of dark-adapted plants were illuminated with red light (RL: 600 μmol m⁻² s⁻¹) for 1 h, after which blue light (BL: 10 μmol m⁻² s⁻¹) was superimposed on RL for 20 min. The data represent means ± SD (n = 9 biologically independent plants). b Time taken to reach 30% of the maximum values of stomatal conductance in response to RL and BL. The data represent means ± SD (n = 9 biologically independent plants). Different letters indicate significant differences (One-way ANOVA with Tukey’s test, P < 0.05). c Quantification of stomatal conductance changes in response to RL and BL. The data represent means ± SD (n = 9 biologically independent plants). Different letters indicate significant differences (One-way ANOVA with Tukey’s test, P < 0.05). d Light-dependent stomatal opening. Epidermal strips were incubated in the dark or under RL (50 µmol m⁻² s⁻¹) with BL (10 µmol m⁻² s⁻¹) for 2 h. The data represent means ± SD (n = 75 stomata from three independent experiments). Different letters indicate significant differences (One-way ANOVA with Tukey’s test, P < 0.01). e Blue light-dependent H⁺ pumping. Guard cell protoplasts were illuminated with RL (300 µmol m⁻² s⁻¹) for 2 h, after which a BL pulse (100 µmol m⁻² s⁻¹, 30 s) was superimposed. f Quantification of the magnitude of H⁺ pumping. The data represent means ± SD (n = 3 biologically independent experiments). Different letters indicate significant differences (One-way ANOVA with Tukey’s test, P < 0.01).