Fig. 2.

Stomata of ABA receptor quadruple mutants are responsive to CO₂ concentration changes. Time-resolved stomatal conductance responses to changes in [CO₂] in Col-0 (WT), pyr1/pyl1/pyl2/pyl4 (rcar10/11/12/14) quadruple mutant (pyr1/pyl1/2/4), and pyr1/pyl4/pyl5/pyl8 (rcar3/8/10/11) quadruple mutant (pyr1/pyl4/5/8) leaves. CO₂ concentrations are shown on top of the data traces in each panel. (A) Absolute average stomatal conductances of WT and pyr1/pyl1/2/4 quadruple mutant leaves. (B) The corresponding relative stomatal conductance responses shown in A. (C) Absolute average stomatal conductances of WT and pyr1/pyl4/5/8 quadruple 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 transition. WT controls are the same because mutants and WT were analyzed in parallel. n = 5 plants for each genotype in all panels. Data represent mean ± SEM. *P < 0.05, **P < 0.01 as analyzed by one-way ANOVA followed by a Dunnett’s test compared with WT control. Data in A–G represent one of three sets of experiments showing similar results.