Fig. 4.

RWC, relative size of the stomatal aperture and stomatal density of the WT and SL- deficient and SL-signaling max mutant plants. (A) Time course of RWC of WT and SL-deficient max3-11 and max4-7 and SL-signaling max2-3 plants exposed to dehydration stress. Data represent the mean and SE (n = 5, where each replicate represents the weight of six plants). Room temperature and relative room humidity data recorded during the course of the experiment are also presented. (B) Average size of the stomatal aperture of rosette leaves from 3-wk-old WT and max mutant plants in the presence or absence of ABA presented as a percentage relative to the size of stomatal aperture in WT and mutant plants not exposed to ABA, which was defined as 100%. Epidermal peels were treated with ABA for 1 h after stomatal preopening under light conditions. Data represent the mean and SD (n = 200). (C) Guard cells of 3-wk-old WT and max mutant plants exposed to 30 µM ABA for 1 h or left unexposed. (Scale bars: 20 µm.) (D) Average stomatal density on the abaxial and adaxial sides of rosette leaves from 3-wk-old WT and max mutant plants. Data represent the mean and SD (n = 30). Asterisks indicate significant differences as determined by a Student t test (*P < 0.05, **P < 0.005, and ***P < 0.001).