Fig. 3.

Stomata of ABA receptor quintuple and hextuple mutants show attenuated stomatal conductance responses to CO₂ concentration changes. Time-resolved stomatal conductance responses to changes in [CO₂] in Col-0 (WT), pyr1/pyl2/pyl4/pyl5/pyl8 (rcar3/8/10/11/14) quintuple mutant (pyr1/pyl2/4/5/8), and pyr1/pyl1/pyl2/pyl4/pyl5/pyl8 (rcar3/8/10/11/12/14) hextuple mutant (pyr1/pyl1/2/4/5/8) leaves. CO₂ concentrations are shown on top of the data traces in each panel. (A) Absolute average stomatal conductances of WT and pyr1/pyl2/4/5/8 quintuple mutant leaves. (B) The corresponding relative stomatal conductance responses shown in A. (C) Absolute stomatal conductance of WT and pyr1/pyl1/2/4/5/8 hextuple mutant leaves. (D) The corresponding relative stomatal conductance responses shown in C. Relative stomatal conductances were calculated by normalizing to the average stomatal conductance at 360 ppm CO₂. Note that data from WT leaves in A and C are the same because the data were obtained in the same experimental dataset. Absolute reduction in stomatal conductance after switching from 360 to 800 ppm CO₂ for (E) 10 min or (F) 40 min. (G) Average half-response times to 800 ppm CO₂. WT controls are the same because mutants and WT were analyzed in parallel. n = 5 plants for WT, n = 4 plants for pyl1/pyl2/4/5/8, and n = 4 plants pyl1/pyl1/2/4/5/8. Data represent mean ± SEM. **P < 0.01, ****P < 0.0001 as analyzed by one-way ANOVA followed by a Dunnett’s test compared with WT control. Data represent one of three independent sets of experiments showing similar results.