Figure 6.

Blue light-induced relative apoplastic acidification rate and proton fluxes of abaxial epidermal strips of young expanding leaves of wt and pcd2 in the presence or absence of 20 µM ABA or t,t-ABA, measured with MIFE. (A) The effect of ABA and t,t-ABA on initial acidification rate in wt and pcd2. (B) Recovery of the blue light-induced apoplastic acidification rate after ABA was removed from the experimental solution. (C) The effect of the ABA and t,t-ABA on blue light-induced proton fluxes in wt and pcd2 mutants. The data are presented as the percentage of the average of the response induced by three blue light pulses given at the start of the experiment in control solution. Values are the means ± SE of at least three independent experiments. The letters above the bars indicate the statistical group of the results from a one-way ANOVA, with Newman-Keuls as post test, α = 0.05. BL = blue light (100 µmol m⁻²s⁻¹).