title: Differential recruitment of WOX transcription factors for lateral development and organ fusion in Petunia and Arabidopsis.
abstract: Petal fusion in petunia (Petunia x hybrida) results from lateral expansion of the five initially separate petal primordia, forming a ring-like primordium that determines further development. Here, we show that MAEWEST (MAW) and CHORIPETALA SUZANNE (CHSU) are required for petal and carpel fusion, as well as for lateral outgrowth of the leaf blade. Morphological and molecular analysis of maw and maw chsu double mutants suggest that polarity defects along the adaxial/abaxial axis contribute to the observed reduced lateral outgrowth of organ primordia. We show that MAW encodes a member of the WOX (WUSCHEL-related homeobox) transcription factor family and that a partly similar function is redundantly encoded by WOX1 and PRESSED FLOWER (PRS) in Arabidopsis thaliana, indicating a conserved role for MAW/WOX1/PRS genes in regulating lateral organ development. Comparison of petunia maw and Arabidopsis wox1 prs phenotypes suggests differential recruitment of WOX gene function depending on organ type and species. Our comparative data together with previous reports on WOX gene function in different species identify the WOX gene family as highly dynamic and, therefore, an attractive subject for future evo-devo studies.
authors.affiliation: Department of Plant Genetics, Institute for Water and Wetland Research, Radboud University Nijmegen, 6525 ED, Nijmegen, The Netherlands. m.vandenbussche@science.ru.nl
authors.forename: Michiel
authors.initials: M
authors.lastname: Vandenbussche
authors.forename: Anneke
authors.initials: A
authors.lastname: Horstman
authors.forename: Jan
authors.initials: J
authors.lastname: Zethof
authors.forename: Ronald
authors.initials: R
authors.lastname: Koes
authors.forename: Anneke S
authors.initials: AS
authors.lastname: Rijpkema
authors.forename: Tom
authors.initials: T
authors.lastname: Gerats
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020285:Cryoelectron Microscopy; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D032306:Petunia / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000648:ultrastructure; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010940:Plant Proteins; D014157:Transcription Factors; C525391:WOX2 protein, Arabidopsis