title: Molecular Aspects of Conifer Zygotic and Somatic Embryo Development: A Review of Genome-Wide Approaches and Recent Insights.
abstract: Genome-wide profiling (transcriptomics, proteomics, metabolomics) is providing unprecedented opportunities to unravel the complexity of coordinated gene expression during embryo development in trees, especially conifer species harboring "giga-genome." This knowledge should be critical for the efficient delivery of improved varieties through seeds and/or somatic embryos in fluctuating markets and to cope with climate change. We reviewed "omics" as well as targeted gene expression studies during both somatic and zygotic embryo development in conifers and tentatively puzzled over the critical processes and genes involved at the specific developmental and transition stages. Current limitations to the interpretation of these large datasets are going to be lifted through the ongoing development of comprehensive genome resources in conifers. Nevertheless omics already confirmed that master regulators (e.g., transcription and epigenetic factors) play central roles. As in model angiosperms, the molecular regulation from early to late embryogenesis may mainly arise from spatiotemporal modulation of auxin-, gibberellin-, and abscisic acid-mediated responses. Omics also showed the potential for the development of tools to assess the progress of embryo development or to build genotype-independent, predictive models of embryogenesis-specific characteristics.
authors.affiliation: FCBA, Pôle Biotechnologie et Sylviculture Avancée, Campus Forêt-Bois de Pierroton, 71 Route d'Arcachon, Cestas, 33610, France. jean-francois.trontin@fcba.fr.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Trontin
authors.affiliation: Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., 10380, Stn. Sainte-Foy, QC, Canada, G1V 4C7.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Klimaszewska
authors.affiliation: INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, Orléans Cedex 2, 45075, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Morel
authors.affiliation: Scion, Private Bag 3020, Rotorua, New Zealand.
authors.forename: Catherine
authors.initials: C
authors.lastname: Hargreaves
authors.affiliation: INRA, UR 0588 Unité Amélioration, Génétique et Physiologie Forestières, 2163 Avenue de la Pomme de Pin, CS 4001, Ardon, Orléans Cedex 2, 45075, France.
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Lelu-Walter
mesh_terms: D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D005838:Genotype; D019684:Magnoliopsida / Q000235:genetics / Q000254:growth & development; D063245:Plant Development / Q000235:genetics*; D058439:Plant Somatic Embryogenesis Techniques / Q000379:methods*; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D064028:Tracheophyta / Q000235:genetics / Q000254:growth & development*
keywords: Developmental regulator; Embryo patterning; Gymnosperm; Metabolome; Proteome; Somatic embryo genesis; Stress; Transcriptome