title: A transcriptomic resource for Douglas-fir seed development and analysis of transcription during late megagametophyte development.
abstract: Douglas-fir transcriptomics. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is economically important with extensive breeding programs and seed trade. However, the molecular genetics of its seed development are largely unknown. We developed a transcriptome resource covering key developmental stages of megagametophytes over time: prefertilization, fertilization, embryogenesis, and early, unfertilized abortion. RNA sequencing reads were assembled de novo into 105,505 predicted high-confidence transcripts derived from 34,521 predicted genes. Expression levels were estimated based on alignment of the original reads to the reference. Megagametophytes express a distinct set of genes compared to those of vegetative tissues. Transcripts related to signaling, protein turnover, and RNA biogenesis have lower expression values in vegetative tissues, whereas cell wall remodeling, solute transport, and seed storage protein transcripts have higher expression values in megagametophytes. Seed storage protein transcripts become very abundant in both pollinated and unpollinated megagametophytes over time, even in aborting ovules. However, the absence of protein storage bodies in unfertilized megagametophytes suggests extensive posttranscriptional mechanisms that either inhibit storage protein translation or their aggregation into protein bodies. This novel transcriptome resource provides a foundation for further important insights into conifer seed development.
authors.affiliation: Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.|Laboratoire Écologie, Systématique, Évolution, CNRS UMR 8079, Université Paris-Sud, 91405, Orsay, France.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Little
authors.affiliation: Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Boyes
authors.affiliation: Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.
authors.forename: Kate
authors.initials: K
authors.lastname: Donaleshen
authors.affiliation: Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: von Aderkas
authors.affiliation: Department of Biology, University of Victoria, Victoria, BC, V8W 3N5, Canada. je@uvic.ca.
authors.forename: Jürgen
authors.identifier: http://orcid.org/0000-0003-2302-696X
authors.initials: J
authors.lastname: Ehlting
mesh_terms: D005306:Fertilization; D058977:Molecular Sequence Annotation; D056771:Ovule / Q000196:embryology / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics; D028224:Pseudotsuga / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D012639:Seeds / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D017423:Sequence Analysis, RNA; D059467:Transcriptome
chemical_list: D010940:Plant Proteins
keywords: Douglas-fir; Fertilization; Megagametophyte; Seed; Storage; Transcriptome