title: On the origin of floral morphological novelties.
abstract: Floral morphological novelties, like homeotic changes of whorl 1 organs, can easily arise by modifying existing regulatory networks. Ectopic expression of B-function MADS-box genes in whorl 1 leads to a replacement of sepals by petals, as is found in the Liliaceae. In cases where leaf-like sepals or even inflated calyces develop, which ultimately envelop the mature fruit as in Physalis, ectopic expression of a vegetative MADS-box gene seems to be responsible. Current knowledge concerning the origin of such morphological novelties is reviewed.
authors.affiliation: Max-Planck-Institute for Breeding Research, Carl-von-Linné Weg 10, 50829 Cologne, Germany.
authors.forename: Chaoying
authors.initials: C
authors.lastname: He
authors.forename: Thomas
authors.initials: T
authors.lastname: Münster
authors.forename: Heinz
authors.initials: H
authors.lastname: Saedler
mesh_terms: D005075:Biological Evolution; D035264:Flowers / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D014644:Genetic Variation; D026161:MADS Domain Proteins / Q000235:genetics / Q000502:physiology*; D010641:Phenotype; D010940:Plant Proteins / Q000502:physiology; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000502:physiology*
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins; D014157:Transcription Factors