Figure 5.

Hypothesis on the regulation of class C dependent B gene expression in E. californica. This modified BCE model of E. californica floral organ identity specification includes the B class genes (orange boxes) EScaDEF1, EScaDEF2, and EScaGLO that are supposed to be expressed in second and third (stamen) whorl. Expression of EScaDEF1 is also found in the central whorl. Two class C genes (green boxes) are expressed in the stamen and central whorl, and the two class E genes EScaAGL2 and EScaAGL9 (blue boxes) are expressed in all whorls except for the sepal whorl for EScaAGL9 [43] while no information is available on the expression domain of EScaAGL2. Red bars indicate repression of gene expression. It remains unclear by which mechanism EScaAG1 and EScaAG2 expression is restricted to the reproductive whorls of the flower and if repression of EScaDEF2 and EScaGLO by the two class C genes is direct or mediated by a co-factor. An A function has not yet been described in California poppy.