title: The PERIANTHIA gene encodes a bZIP protein involved in the determination of floral organ number in Arabidopsis thaliana.
abstract: Mutations in the PERIANTHIA (PAN) gene of Arabidopsis thaliana specifically transform flowers from tetramerous to largely pentamerous, which is a characteristic of flowers of ancestral plants. We have cloned the PAN gene and here we show that it encodes a member of the basic region/leucine zipper class of transcription factors. Immunohistochemical analysis shows that the encoded protein is present in the apical meristem, the floral meristem, each whorl of organ primordia, and in ovule primordia during wild-type flower development. PAN expression occurs independently of genes affecting floral meristem identity, floral meristem size, or floral organ number. The near absence of a phenotype in transgenic plants overexpressing PAN and the contrast between the broad expression of PAN and the specificity of its mutant phenotype suggest that its activity may be regulated post-translationally or by the presence of partner proteins. Based on these results and on data reported previously, we propose models for the role of PAN in the evolution of flower pattern in the mustard family.
authors.affiliation: Division of Biology 156-29, California Institute of Technology, Pasadena, California 91125 USA.
authors.forename: C F
authors.initials: CF
authors.lastname: Chuang
authors.forename: M P
authors.initials: MP
authors.lastname: Running
authors.forename: R W
authors.initials: RW
authors.lastname: Williams
authors.forename: E M
authors.initials: EM
authors.lastname: Meyerowitz
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins; D001483:Base Sequence; D003001:Cloning, Molecular; D018744:DNA, Plant; D004268:DNA-Binding Proteins / Q000235:genetics*; D015870:Gene Expression; D017343:Genes, Plant; D005973:Glutamine; D018398:Homeodomain Proteins / Q000235:genetics; D016350:Leucine Zippers; D026161:MADS Domain Proteins; D018519:Meristem; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics / Q000502:physiology*; D018749:RNA, Plant; D013347:Subcellular Fractions; D014157:Transcription Factors / Q000235:genetics*