Figure 6.

Photosynthetic inhibitors further reduced abscisic acid (ABA)‐induced stomatal closure in epidermal strips treated with NADPH oxidase inhibitor. (a) Effect of DCMU on ABA‐induced stomatal closure in NADPH oxidase inhibitor (diphenyleneiodonium, DPI)‐treated strips of Arabidopsis epidermis. (b) Effect of DBMIB on ABA‐induced stomatal closure in DPI‐treated strips of Arabidopsis epidermis. (c) Effect of DCMU on ABA‐induced stomatal closure in DPI‐treated strips of commelina epidermis. (d) Effect of DBMIB on ABA‐induced stomatal closure in DPI‐treated strips of commelina epidermis. (e) Effect of DCMU on ABA‐induced stomatal closure in DPI‐treated strips of fava bean epidermis. (f) Effect of DBMIB on ABA‐induced stomatal closure in DPI‐treated strips of fava bean epidermis. Epidermal strips containing preopened guard cells were pretreated with 10 μM DCMU, 0.2 μM DBMIB and/or 10 μM DPI for 20 min and then incubated with 10 μM ABA for 2 hr. Experiments were conducted at 23°C in the light (50 μmol m⁻² s⁻¹). Error bars represent standard error of the mean (n = 100). Different letters indicate significant differences at p < 0.01