PIN2 silencing delays activation of AR primordia by flooding. A, Relative expression of SdPIN2 in the AR primordia in control and 24-h submerged plants in the wild type (WT) and PIN2-RNAi lines. Order of lines is according to significance of difference with the wild type. Data are means ± se (n = 2–4). **, Line significantly different from the wild type, two-way ANOVA, P < 0.01; ***, P < 0.001. B, Time to emergence of ARs after start of flooding. Data are means ± se (n = 30 individuals for the wild type and 8–15 for other types; in all cases 15 AR primordia per individual). Difference from the wild type is indicated in parentheses. **, Significantly different from the wild type, one-way ANOVA, P < 0.01; ***, P < 0.001.