title: Changes in cis-regulatory elements of a key floral regulator are associated with divergence of inflorescence architectures.
abstract: Higher plant species diverged extensively with regard to the moment (flowering time) and position (inflorescence architecture) at which flowers are formed. This seems largely caused by variation in the expression patterns of conserved genes that specify floral meristem identity (FMI), rather than changes in the encoded proteins. Here, we report a functional comparison of the promoters of homologous FMI genes from Arabidopsis, petunia, tomato and Antirrhinum. Analysis of promoter-reporter constructs in petunia and Arabidopsis, as well as complementation experiments, showed that the divergent expression of leafy (LFY) and the petunia homolog aberrant leaf and flower (ALF) results from alterations in the upstream regulatory network rather than cis-regulatory changes. The divergent expression of unusual floral organs (UFO) from Arabidopsis, and the petunia homolog double top (DOT), however, is caused by the loss or gain of cis-regulatory promoter elements, which respond to trans-acting factors that are expressed in similar patterns in both species. Introduction of pUFO:UFO causes no obvious defects in Arabidopsis, but in petunia it causes the precocious and ectopic formation of flowers. This provides an example of how a change in a cis-regulatory region can account for a change in the plant body plan.
authors.affiliation: Department of Molecular Cell Biology, VU-University, de Boelelaan 1087, Amsterdam 1081HV, The Netherlands.
authors.forename: Elske
authors.initials: E
authors.lastname: Kusters
authors.affiliation: Department of Molecular Cell Biology, VU-University, de Boelelaan 1087, Amsterdam 1081HV, The Netherlands.
authors.forename: Serena
authors.initials: S
authors.lastname: Della Pina
authors.affiliation: Department of Molecular Cell Biology, VU-University, de Boelelaan 1087, Amsterdam 1081HV, The Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: Castel
authors.affiliation: Department of Molecular Cell Biology, VU-University, de Boelelaan 1087, Amsterdam 1081HV, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Souer
authors.affiliation: Department of Molecular Cell Biology, VU-University, de Boelelaan 1087, Amsterdam 1081HV, The Netherlands Department of Plant Development and (Epi)Genetics, Swammerdam Institute of Life Sciences, University of Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands ronald.koes@uva.nl.
authors.forename: Ronald
authors.initials: R
authors.lastname: Koes
mesh_terms: D032161:Antirrhinum; D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D035264:Flowers / Q000254:growth & development* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology*; D018551:Solanum lycopersicum; D018519:Meristem / Q000254:growth & development* / Q000378:metabolism; D008969:Molecular Sequence Data; D032306:Petunia; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D017931:DNA Primers; C074747:LFY protein, Arabidopsis; D014157:Transcription Factors; C098247:UFO protein, Arabidopsis
keywords: Cyme; Evo-Devo; Inflorescence; Raceme