Figure 8
Stomatal aperture and reactive oxygen species production in leaves of transgenic plants with ABA. A: ABA-induced stomata closure. Four week-old mature leaves of wild-type (WT), 35S::MIR394a and 35S::m5LCR plants were incubated in stomatal opening solution for 2 h and transferred to solutions containing the indicated concentrations of ABA for 2 h. Stomata on the abaxial surface were observed using light microscopy. B: Measurement of stomatal aperture after ABA treatment. At least 60 stomatal cells from each sample were measured. C and D: Detection of ABA-induced O2– and H2O2 accumulation in the leaves of the plants. Leaves from four week-old plants were treated with 0 or 50 μM ABA for 2 h and transferred to 0.1 mg mL-1 nitroblue tetrazolium (C) and 0.1 mg mL-1 3,3’-diaminobenzidine (D) solution for 2 h. The color representing the O2– and H2O2 abundance in the leaves were visualized and photographed. For 35S:MIR394b plants, similar results were found (data not shown). Vertical bars represent standard deviation of the mean (n =3, treatments with 60 seedlings). Asterisks indicate the significant difference between the transgenic lines/mutants and wild-type (WT) (P<0.05).