Fig. 2

Effects of stomatal density (SD) and abscisic acid (ABA) levels on gas-exchange under control and high temperature treatment. Stomatal conductance (g_s) under control and high temperature treatment for (a) NILs (n = 9–11 plants for control and n = 10–13 plants for high temperature treatment) and (b) ZmAbh mutants and their wild type (WT; n = 6–7 plants for both treatments). For the NILs, light blue and green bars indicate genotypes with low or high stomatal density, respectively. For the WT and mutant lines, orange and grey bars indicate genotypes with low or high stomatal density, respectively. CO₂ assimilation rate (A) measured in the same conditions for NILs (c) and mutants (d). Intrinsic water use efficiency (iWUE) calculated from g_s and A for NILs (e) and mutants (f) across conditions. Boxplots represent the median (center line), upper and lower quartiles (box limits), and 1.5 × interquartile range (whiskers). Different letters indicate significant differences in pairwise comparisons within conditions with Benjamini–Hochberg correction (P < 0.05). A two-way ANOVA was performed to assess the effects of genotype, treatment and their interaction for each trait (g_s, A and iWUE). ANOVA derived P-values are listed in Supplementary Table S1.