Project description:Objectives: to characterize and to better understand differences at a protein level in embryonic and non-embryogenic tissues of embryonal masses in Douglas-fir. In Europe, Douglas-fir is a major species for reforestation with increasing demand for its wood. Harvested stems provide timber of outstanding wood quality, mechanical properties and durability. Commercial Douglas-fir plantations in France are limited by the ability to produce seed from the latest breeding developments. Somatic embryogenesis is considered a promising biotechnology for large-scale clonal propagation of forest trees, due to the high multiplication rates it can provide. Moreover, embryogenic cultures are amenable to both cryogenic storage for long-term preservation of genetic resources and genetic engineering (including genome editing) for functional characterization of genes expressed during embryogenesis. In conifers, embryogenic cultures take the form of embryonal mass made up of early differentiated cells forming immature somatic embryos that proliferate via cleavage polyembryony. In Douglas-fir embryogenic lines consisting in embryonal mass have been compared to non-embryogenic callus during their proliferation. Comparison of proteomes (free-gel proteomics) of embryonal mass vs non-embryogenic callus were performed.
Project description:First Douglas fir proteomes by nLC-MS/MS from 12 different organs : root, stem, xylem, needle, bud, female and male flowers, immature and mature seed, immature and mature somatic embryos and callus.
Project description:We developed a transcriptome resource for Douglas-fir covering key developmental stages of megagametophytes over time: prefertilization, fertilization, embryogenesis, and early, unfertilized abortion. Extracted RNA was sequenced using large-scale sequencing and reads were assembled to generate a de novo reference transcriptome of 105,505 predicted high-confidence transcripts. Expression levels were estimated based on alignment of the original reads to the reference.
Project description:Local adaptation and phenotypic plasticity are important components of plant responses to variations in environmental conditions. While local adaptation has been widely studied in trees, little is known about plasticity of gene expression in adult trees in response to ever-changing environmental conditions in natural habitats. Here we investigate plasticity of gene expression in needle tissue between two douglas-fir provenances represented by 25 adult trees using deep RNA sequencing (RNA-Seq). Using linear mixed models, we investigated the effect of temperature, soil water availability and photoperiod on the abundance of 59189 detected transcripts. Expression of more than 80% of all identified transcripts revealed a response to variations in environmental conditions in the field. GO term overrepresentation analysis revealed gene expression responses to temperature, soil water availability and photoperiod that are highly conserved among many plant taxa. However, expression differences between the two Douglas-fir provenances were rather small compared to the expression differences observed between individual trees. Although the effect of environment on global transcript expression was high, the observed genotype by environment (GxE) interaction of gene expression was surprisingly low, since only 21 of all detected transcripts showed a GxE interaction.