ABA maintains AR dormancy and is reduced by flooding and ethylene treatment. A, ABA concentration in primordia and stem of 13-week-old plants after 24 h of various treatments. Around 20 primordia were collected per plant. Data are means ± se (n = 5, each a pool of two plants). Different letters above the bars indicate significant difference between the treatments (ANOVA with Tukey posthoc, P < 0.05). n.a., Not available. B, Effect of ABA treatment on AR emergence and length on 13-week-old plants partially submerged for 7 d. Per plant at least 10 primordia were analyzed. Data are means ± se (n = 5). *, Significantly different from the control, ANOVA, P < 0.05; ***, P < 0.001. C, Effect of ABA synthesis inhibitor fluridone on AR emergence under nonflooded conditions. Per plant 15 primordia were analyzed. Data are means ± se (n = 6). *, Significantly different from the control, ANOVA, P < 0.05. D, Expression of NCED genes upon various treatments. Values for AR primordia and stem are relative to the value of each sample type under control conditions. Data are means ± se (n = 3). *, Significantly different from the control, ANOVA, P < 0.05; ***, P < 0.001. n.a., Not available. E, Expression of an ABA 8′-hydroxylase gene upon various treatments. Values for AR primordia and stem are relative to the value of each sample type under control conditions. Data are means ± se (n = 3). *, Significantly different from the control, ANOVA, P < 0.05. n.a., Not available.