Figure 3. BHP kinase activity is required for stomatal opening in response to blue light.

Functional complementation of stomatal opening by the introduction of the WT BHP gene (a,b) or inactive BHP^D299N gene (c,d) into the bhp-1 mutant. ^# represents an independent transgenic line. (a,c) Expression of BHP protein in leaves of transgenic plants used for complementation experiments in (b,d). Immunoblots of BHP and H⁺-ATPase were performed using proteins prepared from rosette leaves of 3-week-old plants. H⁺-ATPase was used as a loading control. (b,d) Stomatal aperture in the transgenic lines. Data represent means ± SD (n = 4); measurement of 30 stomata in each experiment. *indicates values that statistically differ from the corresponding WT (Student’s t test; *p < 0.01).