Orchestration of floral initiation by APETALA1.
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.
Kaufmann
Kerstin
K
Business Unit Bioscience, Plant Research International, Wageningen 6700 AA, Netherlands.
Wellmer
Frank
F
Muiño
Jose M
JM
Ferrier
Thilia
T
Wuest
Samuel E
SE
Kumar
Vijaya
V
Serrano-Mislata
Antonio
A
Madueño
Francisco
F
Krajewski
Pawel
P
Meyerowitz
Elliot M
EM
Angenent
Gerco C
GC
Riechmann
José Luis
JL
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D047369:Chromatin Immunoprecipitation; D015536:Down-Regulation; D035264:Flowers / Q000254:growth & development*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018745:Genome, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D026161:MADS Domain Proteins / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D024363:Transcription Initiation Site; D014158:Transcription, Genetic; D015533:Transcriptional Activation
C091535:AP1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D018398:Homeodomain Proteins; D026161:MADS Domain Proteins; C121158:SEP3 protein, Arabidopsis; D014157:Transcription Factors