title: Founder-cell-specific transcription of the DORNRÖSCHEN-LIKE promoter and integration of the auxin response.
abstract: Transcription of the DORNRÖSCHEN (DRNL) promoter marks lateral-organ founder cells throughout Arabidopsis development, from cotyledons to flowers or floral organs. In the inflorescence apex, DRNL::GFP depicts incipient floral phyllotaxy, and organs in the four floral whorls are differentially prepatterned: the sepals unidirectionally along an abaxial-adaxial axis, the four petals and two lateral stamens in two putative morphogenetic fields, and the medial stamens subsequently in a ring-shaped domain, before two groups of carpel founder cells are specified. The dynamic DRNL transcription pattern is controlled by three enhancer elements, which redundantly and synergistically control qualitative or quantitative aspects of expression, and differentially integrate the auxin response in Arabidopsis inflorescence and floral meristems. The high sequence conservation of all three enhancer elements among the Brassicaceae is striking, which suggests that densely packed cis-regulatory elements are conserved to recruit multiple transcription factors, including auxin response factors, into higher-order enhanceosome complexes. The spatial organization of the enhancers is also conserved, by a microsynteny that extends beyond the Brassicaceae, which relates to enhancer sharing, as the distal element En1 bidirectionally serves DRNL and the upstream At1g24600 gene; the genes are transcribed in opposite directions and possibly comprise a conserved functional chromatin domain.
authors.affiliation: Institute of Developmental Biology, Biocenter Cologne, University of Cologne, Zuelpicher Str. 47b, 50674 Cologne, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Comelli
authors.affiliation: Institute of Developmental Biology, Biocenter Cologne, University of Cologne, Zuelpicher Str. 47b, 50674 Cologne, Germany.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Glowa
authors.affiliation: Institute of Developmental Biology, Biocenter Cologne, University of Cologne, Zuelpicher Str. 47b, 50674 Cologne, Germany.
authors.forename: John W
authors.initials: JW
authors.lastname: Chandler
authors.affiliation: Institute of Developmental Biology, Biocenter Cologne, University of Cologne, Zuelpicher Str. 47b, 50674 Cologne, Germany Werr@uni-koeln.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Werr
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D056626:Inflorescence / Q000235:genetics / Q000254:growth & development*; D011401:Promoter Regions, Genetic; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D014157:Transcription Factors; C517039:DRNL protein, Arabidopsis
keywords: Arabidopsis; auxin; auxin integration; bi-directional enhancer; founder cell; phylogenetic shadowing; transcriptional control.