ABC model of flower development

“The ABC model was popularized in a review in Nature published later in 1991 by the senior author and Enrico Coen, whose group had been making parallel new findings of similar homeotic mutants in snapdragon. [...] The ABC model is still widely used as a framework for understanding floral development today.”

“Two general conclusions can be reached from the comparison of flower development genes in two distantly related species. The first is that the basic mechanisms that define organ identity in developing flowers appear to be the same in both species. Genes exist whose mutants have similar phenotypes and similar interactions, and a single model can explain the action of these genes in both species.”

“...we may equally well say that a stamen is a contracted petal, as that a petal is a stamen in a state of expansion; or that a sepal is a contracted stem leaf approaching a certain stage of refinement, as that a stem leaf is a sepal expanded by the influx of cruder saps.”