Biology subjects

Labrecque, M.

Publications and source records attributed to Labrecque, M..

3 recordsLinked to original sources

bioRxiv2024

Untargeted metabolomics reveals anion and organ-specific biochemistry of salinity tolerance in willow

1Willows can alleviate soil salinisation while generating sustainable feedstock for biorefinery, yet the metabolomic adaptations underlying their salt tolerance remain poorly understood. Testing two environmentally abundant salts, the response of Salix miyabeana was assessed after treatment with a moderate concentration of NaCl, and both moderate and high concentrations of Na2SO4 in a 12-week pot trial. Willows tolerated salts across all treatments (up to 9.1dS m-1 soil ECe), maintaining photosynthesis and biomass while selectively partitioning ions, confining Na+ to roots and accumulating Cl- and SO 2- in the canopy, and adapting to osmotic stress via reduced stomatal conductance. Untargeted LC-MS/MS captured over 5,000 putative compounds, characterising the baseline willow metabolome, including 278 core compounds constitutively produced across organs. Comparative statistical analyses revealed widespread metabolic reprogramming in response to soil salinity, altering 28% of the overall metabolome, and highlighting organ-tailored regulation. Comparing both salt forms at equimolar sodium, generalised salinity responses were limited to 3% of the metabolome, predominantly in roots. Anion-specific metabolomic responses were more extensive, with NaCl reducing carbohydrates and TCA intermediates, thereby exerting pressure on carbon and energy resources, alongside the accumulation of root structuring compounds, antioxidants flavonoids, and fatty acids. In contrast, Na2SO4 salinity triggered accumulation of sulphur-containing larger peptides, suggesting that excess sulphate incorporation leverage ion toxicity to produce specialized salt-tolerance associated metabolites. This high-depth picture of the willow metabolome underscores the importance of capturing plant adaptations to salt stress at organ-scale and considering ion-specific contributions to soil salinity.

plant biology↗

bioRxiv2023

Comparative Analysis of Methods to Reduce Activation Signature Gene Expression in PBMCs

Preserving the in vivo cell transcriptome is essential for accurate profiling, yet factors during cell isolation including time ex vivo and temperature induce artifactual gene expression, particularly in stress-responsive immune cells. In this study, we investigated two methods to mitigate ex vivo activation signature gene (ASG) expression in peripheral blood mononuclear cells (PBMCs): transcription and translation inhibitors (TTis) and cold temperatures during isolation. Comparative analysis of PBMCs isolated with TTis revealed reduced ASG expression. However, TTi treatment impaired responsiveness to LPS stimulation in subsequent in vitro experiments. In contrast, cold isolation methods also prevented ASG expression; up to a point where the addition of TTis during cold isolation offered minimal additional advantage. These findings highlight the importance of considering the advantages and drawbacks of different isolation methods to ensure accurate interpretation of PBMC transcriptomic profiles. HighlightsO_LITraditional room temperature isolation methods trigger activation signature gene expression in PBMCs, even when rapidly isolated, whereas 4{degrees}C isolation methods do not. C_LIO_LITranscription and translation inhibitors and cold processing techniques reduce activation signature gene expression via shared mechanisms. C_LIO_LIPBMCs treated with transcription and translation inhibitors lose responsiveness to external stimuli. C_LIO_LICold isolation methods offer a suitable and inexpensive alternative to mitigate activation signature gene expression in PBMCs. C_LI

immunology↗

bioRxiv2020

Effect of cleanup of spiked sludge on corn growth biosorption and leaching of metals

AO_SCPLOWBSTRACTC_SCPLOWA chemical leaching process has been used for the cleanup of two municipal biosolids (MOS and BES) spiked with Cd, Cu, Zn or their mixture prior to agricultural use. Non-cleaned, cleaned and washed biosolids were compared as soil amendments for corn cultivation inside glasshouse. Corn growth, biosorption of metals and leaching of these metals in leachate were measured. Results showed that biosolid amendments tend to produce more aerial biomass. Cleanup and washing of BES biosolid significantly augmented total biomass of roots and stalks, respectively. Regarding biosorption of metals, Cd could not be found neither in corn seeds, nor in stalks, while slight amounts of Cu were detected. Whereas Cd and Cu diminished in the order roots > leaves > stalks, Zn diminished from leaves > roots > stalks. Cleanup and washing of MOS and BES biosolids significantly lowered biosorption of Cd, Cu, Zn, and other metals. Leaching into the outlet water varied with time, but average concentrations were moderately low. There were significant amounts of metal leached from MOS biosolid. The effects of cleanup and washing of both biosolids on biosorption and leaching depended on the initial metallic charge and the biosolid type.

plant biology↗