Figure 4.

Abscisic acid (ABA)‐induced reactive oxygen species at guard cell chloroplasts was not eliminated by NADPH oxidase inhibitor. (a) Arabidopsis. (b) commelina. (c) fava bean. Confocal micrographs of guard cells treated with 10 μM ABA for 5 min. Reactive oxygen species and chloroplasts were visualized by H₂ DCFDA fluorescence and autofluorescence of chlorophyll, respectively. Epidermal strips containing preopened guard cells were pretreated with NADPH oxidase inhibitor (10 μM diphenyleneiodonium) for 20 min and then incubated with 10 μM ABA for 5 min. Experiments were conducted at 23°C in the light (50 μmol m⁻² s⁻¹). Bars = 10 μm for a, and 20 μm for b and c