Figure 2.

Effect of ABA on blue light (BL)-induced H⁺-ATPase phosphorylation in stomatal guard cells of the rtl1 mutant. Epidermal fragments of rosette leaves from WT and rtl1 mutant plants were illuminated with red light (RL) for 20 min and then illuminated by BL superimposed on the background RL (RL+BL) for 2.5 min. ABA (20 μM) was added to epidermal fragments 20 min before BL illumination commenced (RL+BL+ABA). (A) Typical images of stomata immunostained using anti-pThr and anti-H⁺-ATPase antibodies. Scale bar = 10 μm. (B) Fluorescent signal intensities from stomata immunostained with anti-pThr antibody. Values represent the mean ± SD (n = 30) in arbitrary units (a.u.). The experiment was repeated three times on different occasions with similar results.