Seed biology

The group "Seed Biology" is investigating the cellular and molecular events that control seed germination and dormancy.

The group's present activities are focused on

  • the signaling role of reactive oxygen
  • the role of post-transcriptional mechanisms in the regulation of seed germination and dormancy.

The objectives of our project are decipher the oxidative mechanisms involved in the transduction of exogenous (temperature and oxygen) or endogenous (eg hormones) signals that regulate seed germination and to determine whether progress towards seed germination is associated with changes in mRNA processing, translatome profile and post-translational protein modifications. In addition the team has a strong experience in translational biology which ensures a rapid transfer of our findings towards the stakeholders.

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The team "Seed Biology" is investigating the cellular and molecular events that control seed germination and dormancy. The group has a very a long-standing experience in seed physiology and is internationally recognized for its expertise in this research area.

The work of the Seed Biology team is focused on the role of reactive oxygen species (ROS) in seed biology and on the molecular regulation of seed germination and dormancy. We associate physiological (germination assays in various environmental conditions), biochemical (ROS chemistry, oxidative processes), molecular (gene expression, protein synthesis) approaches to cell imaging and high throughput technologies (transcriptome, metabolome) for addressing our biological questions. The team is one of the world leaders of ROS and oxygen involvement in seed biology.

The "Seed Biology" team is working with sunflower, barley and Arabidopsis seeds but has also a strong background in translational biology with crop species as shown by the numerous contracts that have been established with private seed companies.

Highlights and future directions

The main objectives of our project are to determine whether reactive oxygen species (ROS) signaling and post-transcriptional mechanisms are key events controlling seed germination and dormancy. We decipher the oxidative mechanisms involved in the transduction of exogenous (temperature and oxygen) or endogenous (eg hormones) signals that regulate seed germination. We pay a special attention to the temporal and spatial dynamics of ROS signaling, a novel concept emerging in plant science. Direct targets of ROS are identified during seed imbibition by studying oxidative modifications of proteins (carbonylation and methionine sulfoxidation) and oxidative modulation of metabolic pathways (evidenced using global metabolomic analyses). 

In addition, we determine whether oxidative post-transcriptional modifications and RNA metabolism may be fundamental regulatory switchboards in seed germination. We investigate the dynamics of the functional state of mRNAs within the messenger ribonucleoproteins (mRNP), i.e. translated mRNPs, stored mRNPs (stress granules) and mRNPs under degradation (P-bodies), as a function of the seed physiological status. Wide transcriptomic approaches allow determining whether progress towards seed germination is associated with changes in transcriptome, translatome (polysomal fraction of mRNA) or other mRNPs associations and if they may exist a link between mRNA oxidation and mRNP metabolism.

Collaborations

  • E. Issakidis-Bourget, IBP-Orsay
  • A. Marion-Poll, H. North, L. Rajjou, IJPB Versailles
  • P. Vincourt, N. Langlade, LIPM, INRA Toulouse
  • JM. Deragon, C. Antonelli-Bousquet, University of Perpignan
  • C. Walters, National Seed Storage Laboratory, Fort Collins (USA)
  • R. Benech-Arnold, D. Battla, University of Buenos-Aires (Argentina)
  • KJ. Bradford, University of Davis (USA)
  • J. Farrant, University of Cape Town (South Africa)
  • D. Rodriguez, O. Lorenzo, University of Salamanca (Spain)
  • M. Holdsworth, University of Nottingham (UK)
  • E. Nambara, University of Toronto (Canada)
  • I. Kranner, University of Innsbrück (Austria)