Objectives

Our general objective is to decipher the molecular mechanisms underlying xylogenesis and involved in the establishment of wood properties. For trees, wood is a vital tissue, necessary for their development and their adaptation to changing environments. It performs three main physiological functions: mechanical support, sap conduction and storage of temporary reserves. For human uses, it is a very important renewable resource for biomaterials, energy and biomolecules, an alternative to fossil carbon and a way of sequestering carbon.

The team is developing functional genomics studies on poplar, a model species for tree biologists, with 1) the production of transgenic or CRISPR-Cas9 genome-edited poplars for selected genes of interest, 2) the fine analysis of transcriptomic and phenotypic modifications of the wood produced by these poplars, 3) the integration of experimental data into biological networks.

The mid-term objectives of the team are:

• to identify the transcriptional regulatory networks involved in the differentiation of cambial cells and the deposition of wood secondary cell walls, by developing innovative approaches at the cellular level in transcriptomics (single cell sequencing) and cell wall microphenotyping (hyperspectral ATR-FTIR imaging).
• to understand the role of the structure of lignins, essential compounds of secondary cell walls, on tree development and wood properties, regarding in particular their acylation and polymerisation.
• to develop cellular engineering methods using Prime Editing in order to broaden the range of tools available for genome editing in poplar and to ease the design of any functional genomics strategy.

These research studies can develop locally thanks to PHENOBOIS platform and LICA laboratory.

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Species

Poplar is the model species. Most of the research activities are done on the INRA 717-1B4 clone (Populus tremula x Populus alba), for its ease to be transformed. For specific studies, some other clones from Populus trichocarpa, Populus nigra or Populus deltoides x P. nigra can be used.

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Additional keywords

Gene networks, Secondary cell wall, Lignins, Molecular histology, Cell engineering

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Team leaders

Annabelle Déjardin (Research officer) & Françoise Laurans (Research engineer)

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Team members

Permanent staff : Nathalie Boizot (Research Engineer), Justine Corret (Assistant engineer), Annabelle Déjardin (Research officer), Françoise Laurans (Research engineer), Gilles Pilate (Research director)

Non-permanent staff : Camille ROSTANT-SANGLIER (Fixed-term contract), Yiyi TAN (PhD student, funding Centre Val de Loire Region 2022-2025), Laura VIMENET (PhD student, funding INRAE - Centre Val de Loire Region 2022-2025)

Yiyi TAN studies the dynamics of secondary cell wall formation in poplar wood fibres using Single Cell techniques.

Laura VIMENET studies the impact of lignin acylation on wood formation, tree development and biomass conversion to energy.

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Current projects

APR-IR/ Centre Val de Loire Region PRESTO (High-throughput prediction of tree and vine vulnerability to biotic and abiotic stresses) - 2020-2023

ANR AAPG21 DEOX (Puzzling out the role of plant and fungal laccases with auxiliary enzymes during depolymerization and polymerization of lignin in a polysaccharide environment) - 2022-2026

PEPR Advanced Plant Breeding TYPEX (Toward highlY Predictable Editing of the plant genome lexicon) - 2023-2028

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Publications

Lien Hal