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Younès dellero

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**Expertise** - Sink-source relationships - Interactions between carbon and nitrogen metabolisms during abiotic stress **Skills** - Metabolomic and fluxomic approaches - Plant physiology - Biochemistry - Functional genetics - Engineering of metabolic pathway <https://orcid.org/0000-0001-6038-8199> - [Google Scholar Profile](https://scholar.google.fr/citations?user=ybE-u6YAAAAJ&hl=fr) - [ReseachGate Profile](https://www.researchgate.net/profile/Younes_Dellero) **Career** **Since 2018**: INRAE Scientist (CRCN) at INRAE Rennes (France). Team « Yield under Abiotic Challenges » (Head: N. Nesi). **2016-2018**: Post-doctoral fellow at the Cell and Plant Physiology Laboratory (Grenoble, France). Team « Biogenesis, dynamics and homeostasis of membrane lipids » (Heads: E. Maréchal and J. Jouhet) **2012-2015**: Ph.D. in Plant Sciences at the Institute of Paris-Saclay Plant Sciences (IPS2, Paris, France). Team « Signaling, regulation and metabolic interactions » (Head: M. Hodges) **2012**: Master of Plant Sciences at the South Paris University, the AgroParisTech School and the National Superior School of Cachan (Paris, France) **2010**: Bachelor in Molecular and Cellular Biology at the South Paris University (Paris, France) **Projects** - **2021-2022**: INRAE Grant (22 k€, TRICYCLE project): “Modelling tricarboxylic acid cycle flux modes in Brassica napus” (PI: Y. Dellero) - **2019-2020**: INRA Grant (30 k€, FLUCOLSA project): “Impact of the sink/source balance on the regulation of metabolic fluxes associated with amino acid metabolism in oilseed rape leaves” (PI: Y. Dellero) **Team «Yield under Abiotic Challenges » focus** [https://www6.rennes.inrae.fr/igepp\_eng/Research-teams/Yield-under-Abiotic-Challenges](https://www6.rennes.inrae.fr/igepp_eng/Research-teams/Yield-under-Abiotic-Challenges) **Organizational Chart of the Team «Yield under Abiotic Challenges »** [https://www6.rennes.inrae.fr/igepp\_eng/Research-teams/Yield-under-Abiotic-Challenges/Staff](https://www6.rennes.inrae.fr/igepp_eng/Research-teams/Yield-under-Abiotic-Challenges/Staff) **Research interests** My research project is part of the team entitled “ Yield under Abiotic Challenges ” and focuses on the regulation of leaf primary metabolism during development and abiotic stress. To gain knowledge on the functioning of major metabolic networks in photosynthetic tissues, I notably develop 13C and 15N-INST-MFA (Isotopically Non-STationary Metabolic Flux Analysis) fluxomic approaches in collaboration with the metabolomic platforms [P2M2](https://www6.inrae.fr/p2m2/Presentation) (Rennes) and MetaToul-metabolic networks (Toulouse) and with the METASYS team from INSA-Toulouse, expert in metabolic flux modelling. I have a particular interest in understanding how the modifications of specific metabolic fluxes allow plants to adapt to developmental and abiotic stress. I am working on the following topics: **1) Amino acid metabolism and mitochondrial respiration during senescence** Senescence is a major process tightly controlled by the hormonal balance that leads to nutrient remobilisation from source-to-sink organs of plants. Senescence can be induced by leaf ageing but also by a wide range of abiotic and biotic stresses. During the first stages of senescence, chloroplasts are extensively degraded in source leaves, leading to the massive production of amino acids, while mitochondria remain operational until the last stages of senescence. Indeed, nutrient remobilisation processes require many energy, which may explain the need to maintain mitochondrial energy production in the absence of functional chloroplasts. Recent works showed that the catabolism of Isoleucine, Leucine, Lysine, Proline, Tyrosine and Valine can significantly contributed to mitochondrial respiration during dark-induced senescence in Arabidopsis. Using transcriptomic, metabolomic and fluxomic approaches, I investigate the importance of these pathways for nutrient remobilization during natural senescence in crops. **2) Flux modes in the plant TriCarboxylic Acid (TCA) cycle** TCA cycle is a major pathway of plant central carbon metabolism. It provides several essential functions for the development and growth of plants by: i) producing reduced NADH and succinate for mitochondrial energy production through the mitochondrial electron transfer chain; ii) producing carbon skeletons for nitrogen assimilation and amino acid biosynthesis (2-oxoglutarate and oxaloacetate notably); iii) recycling the fumarate produced during purine nucleotide biosynthesis. However, TCA cycle enzymes can have multiple subcellular localizations, which further increases the complexity of the interactions of the TCA cycle with other metabolic pathways. Depending on the organ considered and the environmental conditions, the conventional TCA cycle can adopt different flux modes and parts of the TCA cycle have to compete with alternative pathways such as the GABA shunt, the glyoxylate cycle or the PEPc-derived anaplerotic pathway. Using a 13C-INST-MFA fluxomic approach, I am interested in modelling the impact of sink/source relationships and abiotic stress on the topology of TCA cycle. **3) Cross regulations between photosynthesis, photorespiration, mitochondrial respiration and nitrogen assimilation during adaptation to drought stress** When plants perceive a drought stress, roots produce a phytohormone (abscissic acid) that is transported to guard cells of leaves to induce stomatal closure, which in turn decreases water losses by transpiration. However, stomatal closure has major consequences on leaf primary metabolism and plant fitness. First, it decreases the CO2/O2 ratio for RuBiSCO, which in turn decreases net carbon fixation and increases carbon and nitrogen lost by photorespiration. Second, it decreases the negative pressure/tension at the top of the plant and thereafter the xylem-dependent transport of water and nutrients from root-to-shoot. While plants can produce and accumulate compatible osmolytes (proline, betaines, sugars) to cope with long-term drought stress, the adaptation to short-term drought stress requires fine adjustments of leaf primary metabolism that still remain to be investigated. Indeed, major pathways of leaf primary metabolism (photosynthesis, photorespiration, glycolysis, TCA cycle, nitrogen assimilation) are strongly entangled together and are subject to numerous metabolic and redox feedback mechanisms. Using physiological and fluxomic approaches, I characterize the cross regulations between photosynthesis, photorespiration, mitochondrial respiration and nitrogen assimilation operating during adaptation to drought stress.

Publications

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U-13C-glucose incorporation into source leaves of Brassica napus highlights light-dependent regulations of metabolic fluxes within central carbon metabolism

Younès Dellero , Solenne Berardocco , Alain Bouchereau
Journal of Plant Physiology, 2024, 292, pp.154162. ⟨10.1016/j.jplph.2023.154162⟩
Article dans une revue hal-04351796v1
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Why old duplicated genes are not thrown away in (paleo)polyploids? Example from the petC gene in Brassica napus

Maud Facon , Gwenaëlle Deniot , Maryse Lodé-Taburel , Heloise Archambeau , Emilie Montes
Plant Molecular Biology, 2023, Plant Molecular Biology, 113, pp.323-327. ⟨10.1007/s11103-023-01387-9⟩
Article dans une revue hal-04338534v1
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Validation of carbon isotopologue distribution measurements by GC-MS and application to 13 C-metabolic flux analysis of the tricarboxylic acid cycle in Brassica napus leaves

Younès Dellero , Solenne Berardocco , Cécilia Bergès , Olivier Filangi , Alain Bouchereau
Frontiers in Plant Science, 2023, 13, pp.885051. ⟨10.3389/fpls.2022.885051⟩
Article dans une revue hal-03932315v1
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Evaluation of GC/MS-Based 13C-Positional Approaches for TMS Derivatives of Organic and Amino Acids and Application to Plant 13C-Labeled Experiments

Younès Dellero , Olivier Filangi , Alain Bouchereau
Metabolites, 2023, 13 (4), pp.466. ⟨10.3390/metabo13040466⟩
Article dans une revue hal-04045238v1
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DspA/E-triggered non-host resistance against E. amylovora depends on the Arabidopsis GLYCOLATE OXIDASE 2 gene

Alban Launay , Sylvie Jolivet , Gilles Cléme , Marco Zarattini , Younes Dellero
International Journal of Molecular Sciences, 2022, 23 (4224), pp.16-19. ⟨10.3390/ijms23084224⟩
Article dans une revue hal-03637385v1
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Leaf Phenological Stages of Winter Oilseed Rape (Brassica napus L.) Have Conserved Photosynthetic Efficiencies but Contrasted Intrinsic Water Use Efficiencies at High Light Intensities

Younès Dellero , Mathieu Jossier , Alain Bouchereau , Michael Hodges , Laurent Leport
Frontiers in Plant Science, 2021, 12, pp.659439. ⟨10.3389/fpls.2021.659439⟩
Article dans une revue hal-04438260v2
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An Oil Hyper-Accumulator Mutant Highlights Peroxisomal ATP Import as a Regulatory Step for Fatty Acid Metabolism in Aurantiochytrium limacinum

Etienne Deragon , Martin Schuler , Riccardo Aiese Cigliano , Younes Dellero , Gregory Si Larbi
Cells, 2021, 10 (10), ⟨10.3390/cells10102680⟩
Article dans une revue hal-03423342v1
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The Impact of Photorespiratory Glycolate Oxidase Activity on Arabidopsis thaliana Leaf Soluble Amino Acid Pool Sizes during Acclimation to Low Atmospheric CO2 Concentrations

Younes Dellero , Caroline Mauve , Mathieu Jossier , Michael Hodges
Metabolites, 2021, 11 (8), pp.501. ⟨10.3390/metabo11080501⟩
Article dans une revue hal-03330022v1
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Sink/Source Balance of Leaves Influences Amino Acid Pools and Their Associated Metabolic Fluxes in Winter Oilseed Rape (Brassica napus L.)

Younes Dellero , Maud Heuillet , Nathalie Marnet , Floriant Bellvert , Pierre Millard
Metabolites, 2020, 10 (4), pp.150. ⟨10.3390/metabo10040150⟩
Article dans une revue hal-02794472v1
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Manipulating Amino Acid Metabolism to Improve Crop Nitrogen Use Efficiency for a Sustainable Agriculture

Younes Dellero
Frontiers in Plant Science, 2020, 11, ⟨10.3389/fpls.2020.602548⟩
Article dans une revue hal-03030369v1
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Leaf status and environmental signals jointly regulate proline metabolism in winter oilseed rape

Younes Dellero , Vanessa Clouet , Nathalie Marnet , Anthoni Pellizzaro , Sylvain Dechaumet
Journal of Experimental Botany, 2020, 71 (6), pp.2098-2111. ⟨10.1093/jxb/erz538⟩
Article dans une revue hal-02498982v1
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The zoospores of the thraustochytrid Aurantiochytrium limacinum : Transcriptional reprogramming and lipid metabolism associated to their specific functions

Younes Dellero , Cécile Maës , Christian Morabito , Martin Schuler , Caroline C. Bournaud
Environmental Microbiology, 2020, 22 (5), pp.1901-1916. ⟨10.1111/1462-2920.14978⟩
Article dans une revue hal-02613868v1
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The lipid metabolism in thraustochytrids

Christian Morabito , Caroline C. Bournaud , Cécile Maës , Martin Schuler , Riccardo Aiese Cigliano
Progress in Lipid Research, 2019, 76, pp.101007. ⟨10.1016/j.plipres.2019.101007⟩
Article dans une revue hal-02317924v1

Ecophysiology and lipid dynamics of a eukaryotic mangrove decomposer

Younes Dellero , Suzanne Rose , Coralie Metton , Christian Morabito , Josselin Lupette
Environmental Microbiology, 2018, 20 (8), pp.3057-3068. ⟨10.1111/1462-2920.14346⟩
Article dans une revue hal-02046628v1

Proposal of a new thraustochytrid genus Hondaea gen. nov. and comparison of its lipid dynamics with the closely related pseudo-cryptic genus Aurantiochytrium

Younes Dellero , Olivier Cagnac , Suzanne Rose , Khawla Seddiki , Mathilde Cussac
Algal Research - Biomass, Biofuels and Bioproducts, 2018, 35, pp.125-141. ⟨10.1016/j.algal.2018.08.018⟩
Article dans une revue hal-02046577v1

Photorespiratory glycolate–glyoxylate metabolism

Younes Dellero , Mathieu Jossier , Jessica Schmitz , Veronica Maurino , Michael Hodges
Journal of Experimental Botany, 2016, 67 (10), pp.3041-3052. ⟨10.1093/jxb/erw090⟩
Article dans une revue hal-02734557v1

Perspectives for a better understanding of the metabolic integration of photorespiration within a complex plant primary metabolism network

Michael Hodges , Younes Dellero , Olivier Keech , Marco Betti , Agepati S. Raghavendra
Journal of Experimental Botany, 2016, 67 (10), pp.3015-3026. ⟨10.1093/jxb/erw145⟩
Article dans une revue hal-02635801v1

Decreased glycolate oxidase activity leads to altered carbon allocation and leaf senescence after a transfer from high CO2 to ambient air in Arabidopsis thaliana

Younes Dellero , Mathieu Jossier , Nathalie Glab , Céline Oury , Guillaume Tcherkez
Journal of Experimental Botany, 2016, 67 (10), pp.3149-3163. ⟨10.1093/jxb/erw054⟩
Article dans une revue hal-02638226v1
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Arabidopsis thaliana ggt1 photorespiratory mutants maintain leaf carbon/nitrogen balance by reducing RuBisCO content and plant growth

Younes Dellero , Marlène Lamothe Sibold , Mathieu Jossier , Michael Hodges
Plant Journal, 2015, 83 (6), pp.1-15. ⟨10.1111/tpj.12945⟩
Article dans une revue hal-02640240v1
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Experimental evidence for a hydride transfer mechanism in plant glycolate oxidase catalysis

Younes Dellero , Caroline Mauve , Edouard Boex-Fontvieille , Valérie Flesch , Mathieu Jossier
Journal of Biological Chemistry, 2015, 290 (3), pp.1689-1698. ⟨10.1074/jbc.M114.618629⟩
Article dans une revue hal-02634445v1

Using 13C metabolic probes to assess carbon allocation processes within the central metabolism of Brassica napus source leaves

Younes Dellero
2nd Workshop "Carbon allocation in plants": Advances in carbon allocation and acquisition, Nov 2023, Versailles, France
Communication dans un congrès hal-04351791v1

13C measurements and positional approaches with GC-MS: method validation and applications to plant 13C-labeled experiments

Younes Dellero
15e Journées Scientifiques du RFMF, Réseau Francophone de Métabolomique et de Fluxomique (RFMF), May 2023, Perpignan, France
Communication dans un congrès hal-04107676v1

Validation of carbon isotopologue distribution measurements by GC-MS and application to 13C-metabolic flux analysis of the tricarboxylic acid cycle in Brassica napus leaves

Younès Dellero
8th RFMF Webinar, RFMF, Dec 2022, Web Conference, France
Communication dans un congrès hal-04045168v1

Understanding the regulation of proline content in source leaves of winter oilseed rape by using transcriptomic and 15N-isotope tracing approaches

Younes Dellero
European RFMF Metabomeeting 2020, Jan 2020, Toulouse, France
Communication dans un congrès hal-02505896v1