Fig. 8. bif2 is required for spikelet and floral meristem maintenance. (A) Normal spikelet dissected open to reveal the two florets. The lower floret (lf) is flanked by the outer glume (og) and the upper floret (uf) is flanked by the inner glume (ig). Each floret consists of a lemma (l; flanked by the glume), palea (p; separating the flowers), lodicules (not visible) and three stamens (st). Scale bar, 230 µm. (B) bif2 spikelet. The upper floret consists of lemma and palea only while the lower floret is normal. Scale bar, 230 µm. (C) bif2 spikelet. The upper floret is replaced by a filamentous structure (f) and the lower floret has two stamens instead of three. Note that the stamens are deformed. Scale bar, 210 µm. (D) bif2 spikelet consisting of only two glumes and two leaf-like structures that resemble the lemma or palea. Scale bar, 260 µm. (E) Floral organ numbers were counted from florets dissected from 103 spikelets of a bif2 mutant and from 100 spikelets of a normal sibling. Normal florets have a lemma, palea, two lodicules (not counted) and three stamens in both upper and lower florets. bif2 mutants produce fewer organs in both the upper and lower floret, though the upper floret is more severely affected than the lower floret. The percentages refer to the number of florets with the complement of organs shown in the diagram. Green bar, filamentous structure; star, other (florets with lemma and three stamens or palea and one stamen); dash, no floret.