(a,b) Germination phenotypes of wild-type Col, snl1, snl2-1 and snl1snl2. Seeds were after-ripened for 4 months at room temperature before the germination experiment to complete dormancy release (a) or after-ripened and subsequently stratified for 3 days at 4 °C (b). Percentages of seed germination are means (±s.d.) based on the seeds from eight individual plants. Different letters at the same timepoint indicate a significant difference determined by Tukey’s honestly significant difference (HSD) test (P<0.05). (c) Radicle length after 2 days imbibition of after-ripened seeds from Col and snl1snl2-1. The radicles were divided in three groups according to their size. Data are means (±s.e.) of two independent experiments with three technical replicates (N=2, n=3 × 30 seeds). Different letters indicate a significant difference determined by Tukey’s HSD test (P<0.05). (d) Germination percentage of Col and snl1snl2 after exogenous application of auxin synthesis inhibitor AVG (top panel, 40 μM) and auxin transport inhibitors TIBA (middle panel, 25 μM) and NOA (bottom panel, 25 μM). The seeds were after-ripened and stratified. Percentages of seed germination were shown after 12, 18 and 24 h imbibition (±s.d., n=8). Different letters indicate a significant difference determined by Tukey’s HSD test (P<0.05).