Figure 3.

Time constants for stomatal opening (k_open) and closure (k_close) determined by the photosynthesis measurements in four C₃ and five C₄ species grown under HN or LN conditions. A–D, Green and orange boxes indicate C₃ and C₄ species, respectively. Boxplots represent the median (solid black line), first and third quartile (box limits), and maximum and minimum values (whiskers). Significant differences between the species were determined using ANOVA followed by Tukey’s test (P < 0.05) and are indicated by different letters. Data are the mean ± se (n = 4). E, In the relationship between k_open and k_close, solid and dotted lines represent regression line (R² = 0.66, P < 0.01) and 1:1 line, respectively.