Figure 3.

Regulation of stomatal development and function in WT and transgenic mpk4-5 and mpk4-7 plants. A, Expression pattern of genes encoding proteins responsible for environmental control of stomatal development. B, Expression of genes encoding core components of the ABA signaling pathways in stomata. The expression level for (A) and (B) is presented relative to the level in the WT, referred to as 1.0. Presented values are means ± sds (n = 6). C, Stomatal aperture in the WT and mpk4-7 plants after ABA, SNP (NO donor), H₂O₂, and dark treatments presented as representative microphotographs. D, Corresponding stomatal aperture ratio (stomata width/stomata length). C–D, Samples treated with “opening solution” in light conditions were used as a control (for details see “Materials and methods”). The values are the means ± sds (n = 6) of three independent experiments. The asterisks indicate significant differences from the WT revealed by Tukey’s HSD test; *P < 0.05, **P < 0.01, ***P < 0.001.