A Molecular Link between Stem Cell Regulation and Floral Patterning in Arabidopsis

• Published in: Cell 2001-06, Vol.105 (6), p.793-803
• Main Authors: Lohmann, Jan U., Hong, Ray L., Hobe, Martin, Busch, Maximilian A., Parcy, François, Simon, Rüdiger, Weigel, Detlef
• Format: Article
• Language: English
• Subjects: AGAMOUS gene; AGAMOUS Protein, Arabidopsis; Arabidopsis; Arabidopsis - cytology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - physiology; Arabidopsis Proteins; Binding Sites; DNA, Plant - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Gene Expression Regulation, Plant; Genes, Homeobox; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; In Situ Hybridization; Introns; LEAFY protein; Meristem - cytology; Meristem - physiology; Phenotype; Plant Proteins - genetics; Plant Proteins - metabolism; Plant Structures - physiology; Plant Structures - ultrastructure; Plants, Genetically Modified; Regulatory Sequences, Nucleic Acid - genetics; Stem Cells - physiology; Transcription Factors; WUSCHEL protein
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/S0092-8674(01)00384-1

The homeotic gene AGAMOUS (AG) has dual roles in specifying organ fate and limiting stem cell proliferation in Arabidopsis flowers. We show that the floral identity protein LEAFY (LFY), a transcription factor expressed throughout the flower, cooperates with the homeodomain protein WUSCHEL (WUS) to activate AG in the center of flowers. WUS was previously identified because of its role in maintaining stem cell populations in both shoot and floral meristems. The unsuspected additional role of WUS in regulating floral homeotic gene expression supports the hypothesis that floral patterning uses a general meristem patterning system that was present before flowers evolved. We also show that AG represses WUS at later stages of floral development, thus creating a negative feedback loop that is required for the determinate growth of floral meristems.