Loss of BP restores abscission zone placement and the position of the medial sepal-receptacle boundary in as1 mutant flowers. A: bp inflorescence. The flower pedicels are short, slender and point downward. B: as1 bp inflorescence. Abscission of the medial sepals is not delayed. C/D: Scanning electron micrographs of as1 bp flowers (stage 17) showing medial (C) and lateral (D) views. Placement of the abscission zones in as1 bp flowers (D) is similar to that of wild-type (see Figure 2A, E). The abscission zones of as1 bp flowers (C), as previously reported for bp-101, bp-3 and bp-10 flowers ,, show increased cell expansion during fruit development. E/F/I/J: Medial (E/F) and lateral (I/J) views of bp and as1 bp flowers (stage 17). The positions of the enlarged abscission zones of bp (E/I) and as1 bp (F/J) flowers are similar to those of wild-type flowers (see Figure 3A, E). G/H/K/L: Scanning electron micrographs of bp and as1 bp medial sepal primordia. Boundary regions between the medial sepal primordia and underlying flower pedicels are indicated by arrowheads. G: In bp flowers (stage 9), the pedicels are slender and the receptacle region beneath the floral organs fails to expand. H: Displacement of the sepal-receptacle boundary is not evident in as1 bp flowers (stage 9) or bp flowers (G). K/L: Due to radial constriction of the pedicel, the boundary between the sepals and receptacle is less distinct in bp (K) and as1 bp (L) flowers (stage 11). Scale bars: 1°Cm (A/B); 100 μm (C/D/G/H/K/L); 200 μm (E/F/I/J).