FIGURE 3.

Reduced tolerance of CaAIMK1-silenced pepper plants to drought stress. (A) Drought susceptibility of CaAIMK1-silenced pepper plants. Empty vector control and CaAIMK1-silenced pepper plants were grown in pots for 3 weeks under well-watered conditions. The plants were subjected to drought stress by withholding watering for 18 days and then re-watering for 2 days. Representative images were taken before (left) and after (middle) drought treatment and after 2 days of re-watering (right). The survival rates were counted after 2 days of re-watering. Data represent the mean ± standard error of three biological replicates, each evaluating 30 plants. (B) Transpirational water loss from the leaves of empty vector control and CaAIMK1-silenced pepper plants at various time points after leaf detachment. Data represent the mean ± standard error of three biological replicates, each evaluating 40 leaves. (C) Decreased leaf temperatures of empty vector control and CaAIMK1-silenced pepper plants after abscisic acid (ABA) treatment. Data represent the mean ± standard error of three biological replicates, each evaluating 10 plants. (D,E) Stomatal apertures in empty vector control and CaAIMK1-silenced pepper plants after ABA treatment. Representative images were taken under a microscope (D) and the stomatal apertures were measured (E). Leaf peels were harvested from 3-week-old pepper plants and incubated in stomatal opening solution containing 0, 10, or 20 μM ABA; the stomatal apertures were then measured under a microscope. Data represent the mean ± standard error of three biological replicates, each evaluating 20 plants. Asterisks indicate significant differences between control and CaAIMK1-silenced pepper plants (Student’s t-test; * P < 0.05, *** P < 0.001).