title: Molecular control of normal and acrocona mutant seed cone development in Norway spruce (Picea abies) and the evolution of conifer ovule-bearing organs.
abstract: Reproductive organs in seed plants are morphologically divergent and their evolutionary history is often unclear. The mechanisms controlling their development have been extensively studied in angiosperms but are poorly understood in conifers and other gymnosperms. Here, we address the molecular control of seed cone development in Norway spruce, Picea abies. We present expression analyses of five novel MADS-box genes in comparison with previously identified MADS and LEAFY genes at distinct developmental stages. In addition, we have characterized the homeotic transformation from vegetative shoot to female cone and associated changes in regulatory gene expression patterns occurring in the acrocona mutant. The analyses identified genes active at the onset of ovuliferous and ovule development and identified expression patterns marking distinct domains of the ovuliferous scale. The reproductive transformation in acrocona involves the activation of all tested genes normally active in early cone development, except for an AGAMOUS-LIKE6/SEPALLATA (AGL6/SEP) homologue. This absence may be functionally associated with the nondeterminate development of the acrocona ovule-bearing scales. Our morphological and gene expression analyses give support to the hypothesis that the modern cone is a complex structure, and the ovuliferous scale the result of reductions and compactions of an ovule-bearing axillary short shoot in cones of Paleozoic conifers.
authors.affiliation: Department of Organismal Biology, Physiological Botany, Uppsala University, and The Linnean Center for Plant Biology, Ullsv. 24E, SE-756 51, Uppsala, Sweden.
authors.forename: Annelie
authors.initials: A
authors.lastname: Carlsbecker
authors.affiliation: Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and The Linnean Center for Plant Biology, PO Box 7080, SE-75007, Uppsala, Sweden.
authors.forename: Jens F
authors.initials: JF
authors.lastname: Sundström
authors.affiliation: Department of Organismal Biology, Physiological Botany, Uppsala University, and The Linnean Center for Plant Biology, Ullsv. 24E, SE-756 51, Uppsala, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Englund
authors.affiliation: Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and The Linnean Center for Plant Biology, PO Box 7080, SE-75007, Uppsala, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Uddenberg
authors.affiliation: Department of Organismal Biology, Physiological Botany, Uppsala University, and The Linnean Center for Plant Biology, Ullsv. 24E, SE-756 51, Uppsala, Sweden.
authors.forename: Liz
authors.initials: L
authors.lastname: Izquierdo
authors.affiliation: Department of Organismal Biology, Physiological Botany, Uppsala University, and The Linnean Center for Plant Biology, Ullsv. 24E, SE-756 51, Uppsala, Sweden.|Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences and The Linnean Center for Plant Biology, PO Box 7080, SE-75007, Uppsala, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Kvarnheden
authors.affiliation: Laboratorio de Sistemática Molecular (Jardín Botánico), Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, México DF, 04510, Mexico.
authors.forename: Francisco
authors.initials: F
authors.lastname: Vergara-Silva
authors.affiliation: Department of Organismal Biology, Physiological Botany, Uppsala University, and The Linnean Center for Plant Biology, Ullsv. 24E, SE-756 51, Uppsala, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Engström
mesh_terms: D005075:Biological Evolution; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D026161:MADS Domain Proteins / Q000235:genetics*; D009154:Mutation; D063246:Organogenesis, Plant / Q000235:genetics*; D056771:Ovule; D028222:Picea / Q000235:genetics* / Q000254:growth & development; D063245:Plant Development / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics; D018520:Plant Shoots / Q000254:growth & development; D018514:Plant Structures / Q000254:growth & development*; D012098:Reproduction / Q000235:genetics; D012639:Seeds; D064028:Tracheophyta / Q000235:genetics / Q000254:growth & development
chemical_list: D026161:MADS Domain Proteins; D010940:Plant Proteins
keywords: LEAFY genes; MADS-box genes; Picea abies var. acrocona; conifer reproductive development; ovule; ovuliferous scale