title: DORNRÖSCHEN-LIKE expression marks Arabidopsis floral organ founder cells and precedes auxin response maxima.
abstract: Live imaging during floral development revealed that expression of the DORNRÖSCHEN-LIKE (DRNL) gene encoding an AP2-like transcription factor, marks all organ founder cells. Transcription precedes the perception of auxin response maxima as measured by the DR5 reporter and is unaffected in early organogenesis, by mutation of four canonical auxin response elements (AuxREs) in the DRNL promoter. DRNL expression identifies discrete modes of organ initiation in the four floral whorls, from individual or pairs of organ anlagen in the outer whorl of sepals to two morphogenetic fields pre-patterning petals and lateral stamens, or a ring-shaped field giving rise to the medial stamens before carpel primordia are specified. DRNL function only overlaps in the central stem cell zone with that of its paralogue, DORNRÖSCHEN (DRN). drnl mutants are affected in floral organ outgrowth, which functionally interplays with boundary specification as organ fusions are sensitized by loss of CUP-SHAPED COTYLEDON (CUC) gene activity, and synergistic interactions exist with mutants in local auxin biosynthesis and polar transport. DRNL apparently monitors and contributes to cellular decisions in the SAM and thus provides a novel molecular access to the interplay of founder cell specification, organ anlage and organogenesis in the SAM peripheral zone.
authors.affiliation: Institute of Developmental Biology, Cologne Biocenter, Cologne University, Zülpicher Strasse 47b, Cologne, Germany.
authors.forename: John William
authors.initials: JW
authors.lastname: Chandler
authors.forename: Bianca
authors.initials: B
authors.lastname: Jacobs
authors.forename: Melanie
authors.initials: M
authors.lastname: Cole
authors.forename: Petra
authors.initials: P
authors.lastname: Comelli
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*; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D049452:Green Fluorescent Proteins; D007210:Indoleacetic Acids; D014157:Transcription Factors; C426007:CUC1 protein, Arabidopsis; C107294:CUC2 protein, Arabidopsis; C478975:CUC3 protein, Arabidopsis; C517039:DRNL protein, Arabidopsis