A two-way ANOVA was used to determine statistically significant differences between the three treatments and the two maize lines, and P values > 0.05 are marked as NS (not significant). Data are averages ± se (n = 4). Parameters are as follows: leaf length (LL; measured on the fifth leaf at the time of harvesting; Supplemental Fig. S1), LER (calculated during the first 3 d after leaf appearance), mature cell length (Lmat), cell production rate (P), cell division rate (D), cell cycle duration (Tc), length of the meristem (Lmer), number of cells in the meristem (Nmer), time in the division zone (Tdiv), cell elongation rate (Rel), and time in the elongation zone (Tel).