Orchestration of Floral Initiation by APETALA1

• Published in: Science (American Association for the Advancement of Science) 2010-04, Vol.328 (5974), p.85-89
• Main Authors: Kaufmann, Kerstin, Wellmer, Frank, Muiño, Jose M, Ferrier, Thilia, Wuest, Samuel E, Kumar, Vijaya, Serrano-Mislata, Antonio, Madueño, Francisco, Krajewski, Pawel, Meyerowitz, Elliot M, Angenent, Gerco C, Riechmann, José Luis
• Format: Article
• Language: English
• Subjects: activation; Agronomy. Soil science and plant productions; Application programming interfaces; Arabidopsis; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Binding Sites; Biological and medical sciences; Chromatin Immunoprecipitation; Down-Regulation; expression; Flowering; flowering time genes; Flowers & plants; Flowers - growth & development; fruitfull; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Profiling; Gene expression regulation; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genetics and breeding of economic plants; Genome, Plant; Genomics; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; induction; Inflorescences; leafy; MADS Domain Proteins - genetics; MADS Domain Proteins - metabolism; meristem identity; Meristems; microrna; Oligonucleotide Array Sequence Analysis; Plant biology; Plant cells; Plant growth; Plants; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription Initiation Site; Transcription, Genetic; Transcriptional Activation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1185244

The MADS-domain transcription factor APETALA1 (AP1) is a key regulator of Arabidopsis flower development. To understand the molecular mechanisms underlying AP1 function, we identified its target genes during floral initiation using a combination of gene expression profiling and genome-wide binding studies. Many of its targets encode transcriptional regulators, including known floral repressors. The latter genes are down-regulated by AP1, suggesting that it initiates floral development by abrogating the inhibitory effects of these genes. Although AP1 acts predominantly as a transcriptional repressor during the earliest stages of flower development, at more advanced stages it also activates regulatory genes required for floral organ formation, indicating a dynamic mode of action. Our results further imply that AP1 orchestrates floral initiation by integrating growth, patterning, and hormonal pathways.