Expression domains of GhLFY and GhUFO in the IM and FM of wild-type gerbera. A, Expression of GhLFY is absent from the vegetative shoot apical meristem (SAM) and leaves. B, GhLFY shows uniform expression in the young, naked, dome-shaped IM after reproductive transition. C, GhLFY expression marks the incipient flower primordia before their outgrowth (arrow). D, GhLFY first localizes to the adaxial side of incipient bract primordia and later to the axil (arrows) of the elongated involucral bract (iB). E, Expression of GhUFO is lacking from the IM. F, GhUFO expression correlates with FM initiation but occurs later than GhLFY expression (C). G to K, Expression domain of GhLFY during early floral developmental stages. M to Q, Expression domain of GhUFO during early floral developmental stages. L and R, Negative controls were hybridized with sense probes for GhLFY (L) and GhUFO (R). ad, Adaxial; AS, antisense; Ca, carpel; Pa, pappus (sepals of individual flowers); Pe, petal; SE, sense; St, stamen. Bars = 50 µm.