SLs regulate internode elongation by affecting cell number. A, Epidermal cells of internode 4 of the wild type (WT; top left), rms1 (top right), le (bottom left), and le rms1 (bottom right) in scanning electronic microscopy. B, Epidermal cell length (µm) in internode 4 of the wild type, rms1, le, and le rms1. Data are means ± se (n = 7–8 plants with about 100 cells per plant). Values with different lowercase letters are significantly different from one another (ANOVA, P < 0.05). C, Internode 4 length (mm) of the wild type, rms1, le, and le rms1. Values with different lowercase letters are significantly different from one another (ANOVA, P < 0.01). D, Estimation of cell number in internode 4 of the wild type, rms1, le, and le rms. Values with different lowercase letters are significantly different from one another (ANOVA, P < 0.001).