Figure 7.

ABA and oxidative stress insensitivity of ppr96 mutants plants. (A) Growth of Col-0 and mutants plants on ½ MS medium containing zero or 0.5 μM ABA. Bars = 0.5 cm. (B) Comparison of green cotyledon percentages of Col-0 and mutants plants. (C) Germination rates of Col-0 and mutants. Seedlings were grown with or without 1 μM ABA. Germination rates were determined daily after stratificaction. Data represent means ± SD (n = 108). (D) Effects of ABA on root growth of Col-0 and mutants plants. Data represent means ± SD (n = 50) from three independent experiments. (E) Stomatal movement profiles of Col-0 and mutants plants. Stomatal guard cells were observed in the epidermal peels treated with a solution containing 25 mM KCl and 10 mM MES-Tris (pH 6.15) for 1 h in the light and subsequently treated with 10 μM ABA for 3 h. Bars = 10 μm. (F) Stomatal closure of guard cells resulting from ABA treatment. Data are the mean ratios of width to length ± SD of three independent experiments (n = 30). (G) 2-week old Col-0 and ppr96 mutants plants were treated with 10 mM H₂O₂ for 4 d. (H) Reduction of chlorophyll levels in response to H₂O₂ treatment during a 4 d period. (I–L) Expression levels of RAB18, MYB2, ABI5, and AOX1d in Col-0 and ppr96-1 mutant plants under normal conditions and under 1 μM ABA treatment during for 0, 6, and 12 h. Measurement was performed via qPCR. Values represent means ± SD with three biological replicates. Student's t-tests were used to generate the P-values. ^*P < 0.05; ^**P < 0.01.