Fig. 2: WDL7 is degraded during ABA-induced stomatal closure.

a Detached rosette leaves from YFP-tubulin were incubated in opening buffer for 2 h and then treated with 10 μM ABA plus 0 or 20 μM Taxol for 40 min. Scale bar = 10 μm. The graphs show the relative fluorescence of YFP-tubulin and quantitative analysis of microtubule bundling (skewness). Data represent mean ± standard deviation (SD) values from three independent experiments with a minimum of 15 cells each. Different letters represent significant differences at p < 0.01 (one-way ANOVA). b, c Detached rosette leaves from WDL7-GFP transgenic seedlings were incubated in opening buffer for 2 h and then treated with 10 μM ABA, 10 μM ABA plus 20 μM Taxol, 10 μM ABA plus 20 μM Taxol and 50 μM MG132 for 40 min. Confocal images of the guard cells and pavement cells were taken. Scale bar = 10 μm. The graph shows the relative fluorescence of WDL7-GFP in b and c. Data represent mean ± standard deviation (SD) values from three independent experiments with a minimum of 15 cells each. Different letters represent significant differences at p < 0.01 (one-way ANOVA). d Ten-day-old WT seedlings were treated with mock buffer, 10 μM ABA, or 10 μM ABA plus 50 μM MG132 for 1 h and then total proteins were extracted. Purified MBP-WDL7-FLAG was incubated with equal amount of total proteins for the indicated times. MBP-WDL7-FLAG was detected with anti-FLAG antibody. Actin was used as a control. e Quantitative analysis of protein levels in d. The WDL7 protein level at 0 h was set to 1 as a reference for calculating the relative protein levels at the various time points. Data represent the mean ± SD for three independent experiments. Two-tailed Student’s t test, *p < 0.05. f Ten-day-old WDL7-GFP transgenic seedlings were treated with mock buffer, 10 μM ABA, or 10 μM ABA plus 50 μM MG132 for indicated times and then total proteins were extracted from the leaves. WDL7-GFP was detected with anti-GFP antibody. Actin was used as a control. g Quantitative analysis of protein levels in f. The protein level of WDL7-GFP treated with mock buffer was set to 1 as a reference for calculating relative protein levels of various time points. Data represent the mean ± SD for three independent experiments. Two-tailed Student’s t test, *p < 0.05.