RRC ID 6273
Author Kaufmann K, Muiño JM, Jauregui R, Airoldi CA, Smaczniak C, Krajewski P, Angenent GC.
Title Target genes of the MADS transcription factor SEPALLATA3: integration of developmental and hormonal pathways in the Arabidopsis flower.
Journal PLoS Biol
Abstract The molecular mechanisms by which floral homeotic genes act as major developmental switches to specify the identity of floral organs are still largely unknown. Floral homeotic genes encode transcription factors of the MADS-box family, which are supposed to assemble in a combinatorial fashion into organ-specific multimeric protein complexes. Major mediators of protein interactions are MADS-domain proteins of the SEPALLATA subfamily, which play a crucial role in the development of all types of floral organs. In order to characterize the roles of the SEPALLATA3 transcription factor complexes at the molecular level, we analyzed genome-wide the direct targets of SEPALLATA3. We used chromatin immunoprecipitation followed by ultrahigh-throughput sequencing or hybridization to whole-genome tiling arrays to obtain genome-wide DNA-binding patterns of SEPALLATA3. The results demonstrate that SEPALLATA3 binds to thousands of sites in the genome. Most potential target sites that were strongly bound in wild-type inflorescences are also bound in the floral homeotic agamous mutant, which displays only the perianth organs, sepals, and petals. Characterization of the target genes shows that SEPALLATA3 integrates and modulates different growth-related and hormonal pathways in a combinatorial fashion with other MADS-box proteins and possibly with non-MADS transcription factors. In particular, the results suggest multiple links between SEPALLATA3 and auxin signaling pathways. Our gene expression analyses link the genomic binding site data with the phenotype of plants expressing a dominant repressor version of SEPALLATA3, suggesting that it modulates auxin response to facilitate floral organ outgrowth and morphogenesis. Furthermore, the binding of the SEPALLATA3 protein to cis-regulatory elements of other MADS-box genes and expression analyses reveal that this protein is a key component in the regulatory transcriptional network underlying the formation of floral organs.
Volume 7(4)
Pages e1000090
Published 2009-4-21
DOI 10.1371/journal.pbio.1000090
PII 08-PLBI-RA-4384
PMID 19385720
PMC PMC2671559
MeSH Arabidopsis / genetics* Arabidopsis / growth & development Arabidopsis Proteins / genetics* Arabidopsis Proteins / metabolism DNA, Plant / metabolism Flowers / genetics Flowers / growth & development Gene Expression Regulation, Developmental Gene Expression Regulation, Plant* Genes, Homeobox Genes, Plant* Genome-Wide Association Study Homeodomain Proteins / genetics* Homeodomain Proteins / metabolism Indoleacetic Acids MADS Domain Proteins / genetics* Plant Growth Regulators Signal Transduction Transcription Factors / genetics* Transcription Factors / metabolism
IF 7.076
Times Cited 292
WOS Category BIOLOGY BIOCHEMISTRY & MOLECULAR BIOLOGY
Resource
Arabidopsis / Cultured plant cells, genes pst11935 pst20678