Project description:Characterization of bacterial and fungal community dynamics by high-throughput sequencing (HTS) metabarcoding during flax dew-retting
Project description:One of the biggest challenges to a more widespread utilization of natural fibers from flax and other fiber plants is to obtain a better understanding of the different factors underlying the observed variability in fiber quality. To do this, we measured fiber morphometric parameters from seven different flax varieties (4 spring fiber, 2 winter fiber and 1 winter oil) and undertook Partial Least-Squares Discriminant Analysis (sPLS-DA) of transcriptomic data obtained from the same varieties in an attempt to identify high-information molecular markers. The calculation of Pearson correlation coefficients identified 5 putative gene-markers strongly correlated with morphometric features. Proteomic analysis on the two varieties showing the most discriminant and significant differences regarding to morphometrics identified an additional 4 protein-markers. The majority of the obtained markers are involved in lipid metabolism and the senescence process. Further comparative analysis of the obtained expression data with fiber mechanical measurements (strength, maximum force, area) obtained after field-retting for all 7 varieties allowed us to identify 4 highly-correlated putative molecular markers for the mechanical parameters. Three genes, connected directly or indirectly to cell wall metabolism (Expansin-related protein 3 precursor, beta-glucosidase and ascorbate peroxidase), and one gene coding an enzyme that catalyzes the oxidative decarboxylation of L-malate (NADP-malic enzyme 3). Based on our results, we hypothesize that a reduced number of RNA and protein functional markers can be used to more accurately monitor and/or predict fiber yield and quality properties in different flax varieties, thereby contributing to an Agriculture 4.0 for this economically-important species.
Project description:To investigate changes in genome methylation in flax seedlings under drought stress, we selected a drought-tolerant flax variety (Z141) and a drought-sensitive flax variety (NY-17) We then performed genome methylation analysis using data obtained from Z141 and NY-17 leaf tissue BS-seq at four different treatments (DS, RW, RD and CK).
Project description:We developped a new oligo microarray platform to analyse flax transcriptome. Here, we validated this microarray on several tissues of flax, at different developmental stages.
Project description:Performances of flax gene expression analyses were compared in two categories of Nimblegen microarrays (short 25-mers oligonucleotides and long 60-mers oligonucleotides) Results obtained in this study are described in Intra-platform comparison of flax (Linum usitatissimum L.) high-density Nimblegen DNA microarrays submitted to Journal of Computational Biology We compared two categories of flax target probes: short (25-mers) oligonucleotides and long (60-mers) oligonucleotides in identical conditions of target production, design, labelling, hybridization, image analyses, and data filtering. This comparison was realized with two different flax samples and each RNA sample was used for the two categories of arrays. Experiments were realized in order to discriminate specific gene expression profiles of two different flax tissues (outer and inner stem tissues).
Project description:Proteomic analyses of four different flax organs/tissues (inner-stem, outer-stem, leaves and roots) enriched in proteins from 3 different sub-compartments (soluble-, membrane-, and cell wall-proteins) was combined with publically available data on flax seed and whole-stem proteins to generate a flax protein database containing 2996 non-redundant total proteins. Examination of the proteins present in different flax organs/tissues provided a detailed overview of cell wall metabolism and highlighted the importance of hemicellulose and pectin remodeling in stem tissues.
Project description:Whole-genome bisulfite sequencing (WGBS) was employed for identification of differential DNA methylation profiles among control and heat-stressed seedlings of a fibre flax (Linum usitatissimum L.) var., JRF-2. It was identified as a tolerant variety of heat stress-induced oxidative damage. High-quality genomic DNA from four samples comprised 3-week-old control and heat-stressed (40±2°C) seedlings, with or without treated with 5-Azacytidine (hypomethylating agent). High-quality and filtered paired-end Illumina reads were aligned to the flax reference genome, assembled in chromosomes, using bwa-meth tool, followed by methylation loci (5-mC) calling using the MethylDackel software. Differentially methylated regions (DMRs) between the control and other samples were identified using the methylKit and annotated using genomation package for their precedence in the promoter/exon/intron/intergenic regions. The DMRs comprised both hyper- and hypomethylated loci, but the latter found dominated due to heat stress in flax seedlings. The WGBS in flax for heat stress will provide a platform to identify epigenetic loci responsible for heat-stress adaptation in flax.