ROS production and protein oxidation as a novel mechanism for seed dormancy alleviation

Authors

  • Krystyna Oracz,

    1. Department of Plant Physiology, Warsaw Agricultural University, Nowoursynowska 159, 02-776 Warsaw, Poland,
    2. Université Pierre et Marie Curie-Paris 6, EA 2388 Physiologie des Semences, Le Raphaël, Site d’Ivry, Boîte 152, 4 Place Jussieu, Paris F-75005 France,
    Search for more papers by this author
  • Hayat El-Maarouf Bouteau,

    1. Université Pierre et Marie Curie-Paris 6, EA 2388 Physiologie des Semences, Le Raphaël, Site d’Ivry, Boîte 152, 4 Place Jussieu, Paris F-75005 France,
    Search for more papers by this author
  • Jill M. Farrant,

    1. Department of Molecular and Cell Biology, University of Cape Town, Private Bag 7701 Rondebosch, South Africa,
    Search for more papers by this author
  • Keren Cooper,

    1. Department of Molecular and Cell Biology, University of Cape Town, Private Bag 7701 Rondebosch, South Africa,
    Search for more papers by this author
  • Maya Belghazi,

    1. Institut National de la Recherche Agronomique, Unité Mixte de Recherche 6175, Service de Spectrométrie de Masse pour la Protéomique, Nouzilly, F-37380 France, and
    Search for more papers by this author
  • Claudette Job,

    1. Centre National de la Recherche Scientifique/Bayer CropScience Joint Laboratory, Unité Mixte de Recherche 2847, Bayer CropScience, Lyon, F-69283 France
    Search for more papers by this author
  • Dominique Job,

    1. Centre National de la Recherche Scientifique/Bayer CropScience Joint Laboratory, Unité Mixte de Recherche 2847, Bayer CropScience, Lyon, F-69283 France
    Search for more papers by this author
  • Françoise Corbineau,

    1. Université Pierre et Marie Curie-Paris 6, EA 2388 Physiologie des Semences, Le Raphaël, Site d’Ivry, Boîte 152, 4 Place Jussieu, Paris F-75005 France,
    Search for more papers by this author
  • Christophe Bailly

    Corresponding author
    1. Université Pierre et Marie Curie-Paris 6, EA 2388 Physiologie des Semences, Le Raphaël, Site d’Ivry, Boîte 152, 4 Place Jussieu, Paris F-75005 France,
      (fax +33 1 44 27 59 27; e-mail bailly@ccr.jussieu.fr).
    Search for more papers by this author

(fax +33 1 44 27 59 27; e-mail bailly@ccr.jussieu.fr).

Summary

At harvest, sunflower (Helianthus annuus L.) seeds are dormant and unable to germinate at temperatures below 15°C. Seed storage in the dry state, known as after-ripening, is associated with an alleviation of embryonic dormancy allowing subsequent germination at suboptimal temperatures. To identify the process by which dormancy is broken during after-ripening, we focused on the role of reactive oxygen species (ROS) in this phenomenon. After-ripening entailed a progressive accumulation of ROS, namely superoxide anions and hydrogen peroxide, in cells of embryonic axes. This accumulation, which was investigated at the cellular level by electron microscopy, occurred concomitantly with lipid peroxidation and oxidation (carbonylation) of specific embryo proteins. Incubation of dormant seeds for 3 h in the presence of hydrogen cyanide (a compound that breaks dormancy) or methylviologen (a ROS-generating compound) also released dormancy and caused the oxidation of a specific set of embryo proteins. From these observations, we propose a novel mechanism for seed dormancy alleviation. This mechanism involves ROS production and targeted changes in protein carbonylation patterns.

Ancillary