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:Roots of Arabidopsis thaliana do not engage in symbiotic association with mycorrhizal fungi but host taxonomically diverse fungal communities that influence health and disease states. We sequenced the genomes of 41 isolates representative of the A. thaliana root mycobiota for comparative analysis with 79 other plant-associated fungi. We report that root mycobiota members evolved from ancestors having diverse lifestyles and retained diverse repertoires of plant cell wall-degrading enzymes (PCWDEs) and effector-like small secreted proteins. We identified a set of 84 gene families predicting best endophytism, including families encoding PCWDEs acting on xylan (GH10) and cellulose (AA9). These genes also belong to a core transcriptional response induced by phylogenetically-distant mycobiota members in A. thaliana roots. Recolonization experiments with individual fungi indicated that strains with detrimental effects in mono-association with the host not only colonize roots more aggressively than those with beneficial activities but also dominate in natural root samples. We identified and validated the pectin degrading enzyme family PL1_7 as a key component linking aggressiveness of endophytic colonization to plant health.
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.