FIGURE 9.

Plants overexpressing miR167 maintain smaller stomatal apertures. (a) Whole leaves of five‐week‐old Col‐0 and P_35S::MIR167a plants were detached and incubated in water alone or in 5 × 10⁸ cfu/ml Pst DC3000 suspended in water and stomatal apertures were measured at the indicated time points. Asterisks indicate significant differences between wild‐type and P_35S::MIR167a at p < .001 (ANOVA followed by Tukey's HSD post‐hoc tests). (b) Fresh whole leaves of five‐week‐old Col‐0 and P_35S::MIR167a plants were detached and stomatal apertures were immediately measured each hour from lights‐on until lights‐out. Differences between Col‐0 and P_35S::MIR167a were statistically significant at all time points (p < .001, Student's t test). All bars indicate means + SEM for 85 stomata per sample. These experiments were repeated three times with similar results. Results of one such experiment are shown. As P_35S::MIR167a plants are sterile, a population of independent T₁ transgenic plants was used rather than stable transgenic lines