Our research

The aim of our research is to study the effects of some heavy metals and radionuclides (HMR) in the plant model Arabidopsis thaliana. In a context of integrative plant biology, we have developed global functional genomics analysis approaches such as transcriptomics, proteomics and metabolomics combined with targeted genetics approaches and classical biochemical studies in order to analyze the perception of the metal stress by the plant cell and the cascade of events set up to fight against it.
The approaches are aimed at a fairly comprehensive analysis of the impact of those metals on the physiology and metabolism of the plant.

We are seeking to:

Have a global view of the response of both the plant cell and the plant to MLR stresses (cadmium, cesium and uranium): characterize the molecular entities and pathways perturbed by these elements…

The use of "omics" approaches allowed to have this global view of the response of the plant and to highlight the ways of adaptations implemented in order to counter the stress caused by HMR.

Collaborations with: EDyP team at our institute, LEMS (CEA-Cadarache), LEMM (CEA Saclay)…

References:
Doustaly et al. 2014, Villiers et al. 2012, Agrawal et al. 2011, Villiers et al. 2011, Sarry et al. 2006a, 2006b, Ducruix et al. 2006, Herbette et al. 2006, Lelay et al. 2006.

Better understand how the plant perceives the metal stress and what are the different mechanisms involved in the HMR detoxification in respond to this stress. To investigate the role of the vacuole in the metal detoxification

- Demonstration of a new protein involved in the detoxification of cadmium: the 'Selenium Binding Protein' (increased tolerance to Cd of the plants overexpressing SBP1) (Dutilleul et al. 2008, Hugouvieux et al. 2009).

- Highlighting new isoforms of phytochelatins and characterization of the limiting step of the biosynthetic pathway of phytochelatines (Sarry et al. 2006, Ducruix et al. 2006, 2008).

- Characterization of the membrane proteome of the vacuole (Jaquinod et al. 2007)

- Evidence of the existence of the proteasome pathway and of proteases operating downstream of proteasomes in plants and its activation by cadmium (Polge et al. 2009).

Search and dissect the regulatory networks that are activated in response to metal stress (genes / proteins involved in transduction and regulation signals of the gene expression)

- Study of Selenium Binding Protein:
Analysis of its expression related to sulfur deficiency; Highlighting the role of glutathione as a regulator of gene expression (Schild et al, 2014); Biophysical and biochemical characterization of the Arabidopsis thaliana SBP1 (Hugouvieux et al. 2009).

- Research for networks of co-regulated genes (bioinformatic analysis: collaboration the EDyP team at our institute) (Uranium: Doustaly et al. 2014; Cadmium: Boyer et al. 2009).

- Evidence of a functional interaction between brassinosteroids and the cadmium response in Arabidopsis thaliana (Villiers et al. 2012).

Characterization of the micro-algae Coccomyxa actinabiotis

We study microalgae (including Coccomyxa actinabiotis) discovered in cooling pools of spent nuclear elements. Its extraordinary properties: resistance to strong ionizing radiation (20,000 Gy), ability to accumulate heavy metals and radionuclides have been recently studied in our team (Leonardo et al. 2014, Rivasseau et al. 2013).
This micro-algae has been used to develop a biological process for decontaminating nuclear waste (Diane de Gouvion Saint Cyr thesis). This research is done in collaboration with the Department of Nuclear Energy and with the Institut Laue Langevin (contact C. Rivasseau).

Study of the fate of toxic metals and their speciation

The use of µSXRF (Synchrotron Radiation X-Ray Fluorescence), µXANES (X-ray Absorption Near Edge Structure), STIM (Scanning Transmission Ion Microscopy) technics (collaboration with the Chemical Imaging and Speciation CNAB group, UMR 5084 CNRS/University of Bordeaux, ESRF Beamline ID 21, Section d'Applications des traceurs, CEA Grenoble, Marie Carrière group, Inac, CEA-Grenoble)
This kind of study was performed on Arabidopsis thaliana seedlings treated with cadmium, cesium (Déves et al. 2005, Isaure et al. 2006a, 2006b) and on crops (colza, sunflower, wheat) treated in the presence of various forms of uranium (Laurette et al. 2012a, Laurette et al. 2012b).