Fig. 6.

Spatial distribution of AP2-5 and miR172 along the vertical axis of developing spikes. (A,B) Expression levels, as estimated by qRT-PCR, of mature miR172 (A) and AP2-5 combined homoeologs (B). Expression was analyzed in basal (Ba), central (Ce) and apical (Ap) sections of developing spikes of Kronos at three developmental stages: FP, floret primordia (∼1.5 mm); AE, awn elongation (∼2.5 mm); and YS, young spikes (∼10 mm). Expression was also analyzed in sections of MIM172#4 spikes at AE stage. AP2-5 transcript and miR172 levels were normalized to the Kronos basal section at FP stage (n=3). Different letters above the bars indicate statistically significant differences (P<0.05) by Student–Newman–Keuls test. (C) Spikes at the three developmental stages used to study miR172 and AP2-5 expression. Horizontal dotted lines indicate the three sections analyzed. Scale bars: 1 mm.