Team leader
Address
Laboratoire Physiologie Cellulaire & Végétale
CEA-Grenoble
17 avenue des Martyrs
38 054 Grenoble cedex 9
France
Presentation
Intensive agriculture, industrialisation and natural phenomena such as rock erosion all contribute to soil contamination by trace metals, also known as 'heavy metals'. The accumulation of these non-degradable metals in the environment represents a major threat to ecosystems, food safety and human health. Depending on their role in biological systems, metals are classified to as essential or non-essential. Essential heavy metals such as iron, copper, manganese, zinc and nickel are required for plant growth and development by acting as cofactors in various vital physiological and biochemical processes (
e.g. photosynthesis, respiration). However, these elements become toxic when present in excess. Non-essential heavy metals, including cadmium, lead, mercury, chromium, silver, arsenic and uranium, on the other hand, are toxic even at low concentrations and have no known biological function.
Remediation of contaminated soils is necessary to prevent the accumulation, leaching and/or mobilisation of heavy metals by crop species. Phytoremediation is a sustainable, environmentally friendly strategy based on the ability of plants to absorb pollutants, including heavy metals. However, optimising such strategies depends on understanding the molecular mechanisms that allow metals to accumulate in plants, including their uptake, distribution and sequestration, as well as the mechanisms involved in their tolerance, which are sometimes poorly characterised in photosynthetic organisms.
In this context, the MetalStress team aims to decipher the molecular basis of heavy metal tolerance and accumulation in plants and microalgae, using model species known as metal hyperaccumulators or non-accumulators.
The team is currently working on a number of research topics, with a particular focus on uranium, silver and nickel:
- Plant responses to uranium
- Nickel tolerance in plants
- Microalgae tolerant to metal stress
The team uses both global transcriptomic, proteomic, metabolomic and ionomic approaches combined with more targeted approaches combining physiology, genetics, molecular/cellular biology and biochemistry. Equipped with the latest generation of ICP-MS (Inductively Coupled Plasma-Mass Spectrometry), one of the MetalStress team's specialities is multi-elemental analysis in response to
in vivo metal treatments.
In the long term, this fundamental research, upstream of fields of application, could be integrated into programmes for the targeted selection of species adapted to the phytoremediation of environments contaminated by metals.
Key words
Heavy metals, Uranium, Nickel, Pollution, Phytoremediation, Plants, Microalgae
Members of the team
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Main results
- We have shown that the recombinant Arabidopsis PCaP1 protein is able to bind uranium
in vitro with high affinity (in the nanomolar range), but also copper and oxidised iron in very high proportions (up to 60 iron cations per protein monomer). In the course of this work, competition between calcium and uranium atoms for binding in the PCaP1 protein was observed. We also showed that uranium induces PCaP1 oligomerisation
in vitro, and is involved in the translocation of uranium from the roots to the aerial parts.
- We have developed a precise and reliable metalloproteomic approach to isolate and identify uranium-binding proteins from the model plant
Arabidopsis thaliana, elucidating the first 'urano-proteome' of a photosynthetic organism.
- We have showed that the calcium channels MCA1, MCA2 and ANN1 are a major route for uranium uptake in Arabidopsis roots. We have showed that this calcium channel-dependent uranium uptake is also conserved in yeast and may represent a general uranium uptake system, at least in the eukaryotic lineage.
Funding
- INRAE, BAP scientific division, DISTRIBURA project (2022-2024)
- ANR, DemoniaCo project (2022-2025)
- CNRS, DBM program, SilverCoela project (2021-2023)
- INRAE, BAP scientific division, DemoniaCo project (2021-2023)
- INRAE, BAP scientific division, FULGAS project (2020-2022)
- CNRS, NEEDS program, INSPECT project (2020-2024)
- EURATOM Horizon 2020, RadoNorm project (2020-2025)
- CEA, TOXCEA/DRF impulsion, PhospUra project (2018-2019)
- ANR, GreenU project (2018-2022)
Collaborations
LPCV, Chromdev team, Christel CARLES (Grenoble)
LPCV, Lipid team, Juliette JOUHET/ Eric MARECHAL (Grenoble)
LPCV, Photosymbiosis team, Johan DECELLE (Grenoble)
LPCV, Grégory SI LARBI (Grenoble)
CERMAV, Structural and molecular glycobiology team, Olivier LEROUXEL (Grenoble)
LCBM, Team Biology of metals, Patrice CATTY (Grenoble)
LCBM, Proteomics for microbiology, immunology and toxicology team, Thierry RABILLOUD (Grenoble)
IBS, Biomolecular NMR spectroscopy team, Bernhard BRUTSCHER (Grenoble)
BIAM, Protein-metal interactions team, Virginie CHAPON (Cadarache)
BFP, Metabolism team, Sophie COLOMBIE/ Pierre PETRIACQ (Bordeaux)
IAM, Stress response and redox regulation team, Nicolas ROUHIER (Vandoeuvre-lès-Nancy)
IPSIM, Ion flux coordination and signaling in plant cells team, Alexis DE ANGELI (Montpellier)
LRSV, Metal hyperaccumulation team, Sylvain MERLOT (Toulouse)
Phytosystems, Metal homeostasis team, Marc HANIKENNE (Liege, Belgium)
UPSC, Stress-induced senescence and its subsequent metabolic regulations team, Olivier KEECH (Umeå, Sweden)
Dimitris PETROUTSOS (Uppsala, Sweden)