Fig. 2. Schematic summary of experimental observations on the influence of epidermal B function on petal development in Antirrhinum. Autonomous control is indicated by the solid arrows and non-autonomous control is shown by the broken arrows. The contribution of the endogenous DEF/GLO genes in wild-type sepals is indicated in red. All other control events are common to AFI::DEF/GLO wild-type sepals and def (or glo) mutant petals expressing AFI::DEF (or AFI::GLO). The dotted arrows on the right indicate an epidermal influence on petal shape and size, which are also affected by sub-epidermal events (Perbal et al., 1996), not discussed in this report.