RESEARCH ARTICLE Proteomics reveals potential biomarkers of seed vigor in sugarbeet Julie Catusse 1 , Juliane Meinhard 2 , Claudette Job 1 , Jean-Marc Strub 3 , Uwe Fischer 2 , Elena Pestsova 4 , Peter Westhoff 4 , Alain Van Dorsselaer 3 and Dominique Job 1 1 CNRS/UCBL/INSA/Bayer CropScience Joint Laboratory (UMR), Lyon, France 2 KWS SAAT AG, Einbeck, Germany 3 Universite ´ de Strasbourg, IPHC, CNRS, UMR, Strasbourg, France 4 WE (Department) Biologie/Botanik Heinrich-Heine-Universitaet, Duesseldorf, Germany Received: September 13, 2010 Revised: October 21, 2010 Accepted: November 8, 2010 To unravel biomarkers of seed vigor, an important trait conditioning crop yield, a comparative proteomic study was conducted with sugarbeet seed samples of varying vigor as generated by an invigoration treatment called hydropriming and an aging treatment called controlled deterioration. Comparative proteomics revealed proteins exhibiting contrasting behavior between seed samples. Thus, 18 proteins were up-regulated during priming and down- regulated during aging and further displayed an up-regulation upon priming of the aged seeds, meaning that down-regulation of these spot volumes during aging was reversible upon subsequent priming. Also, 11 proteins exhibited the converse behavior characterized by a decrease and an increase of the spot volumes during priming and aging of the control seeds, respectively, and a decrease in the spot volumes upon priming of the aged seeds. The results underpinned the role in seed vigor of several metabolic pathways involved in lipid and starch mobilization, protein synthesis or the methyl cycle. They also corroborate previous studies suggesting that the glyoxylate enzyme isocitrate lyase, the capacity of protein synthesis and components of abscisic acid signaling pathways are likely contributors of seed vigor. Keywords: Aging / Plant proteomics / Priming / Seed vigor / Sugarbeet 1 Introduction Seed vigor exerts a serious impact on plant stand estab- lishment, which poses a strong challenge to produce high- quality seeds for stabilizing crop yield. A key to achieving this is elucidation of the molecular mechanisms underlying this trait. The lifespan of seeds is an important component of seed vigor, which depends on their physiological and genetic conservation potential and on conditions encountered during storage [1, 2]. Lethal damage can be induced rapidly in seeds by controlled deterioration as occurs during natural aging [3, 4]. This treatment, which involves the elevation of seed moisture content and temperature, is frequently used to quickly assess seed quality. Seed vigor also includes uniform germination and seed- ling establishment, which can be enhanced by treatments referred to as seed priming and that proved successful to invigorate the performance of low-vigor seeds [5–7]. Here, seeds are subjected to controlled hydration, so as to initiate germination-related processes but preventing radicle emer- gence. Since in most plant species seeds can remain desic- cation tolerant up to radicle emergence, priming can be followed by a drying permitting storage of the primed seeds. Despite the wide use of these treatments, their optimization currently rests on carrying out germination assays, which These are not the final page numbers Abbreviations: ABA, abscisic acid; AdoMet, S-adenosylmethio- nine; EBP1, ErbB3-binding protein 1; Glc/RibDH, glucose and ribitol dehydrogenase; ICL, isocitrate lyase; IRES, internal ribosome entry sites; OPH, O-phosphohomoserine; TAG, tri- acylglycerol; TOR, target of rapamycin; VDAC, voltage-depen- dent anion channel Correspondence: Professor Dominique Job, CNRS/UCBL/INSA/ Bayer CropScience Joint Laboratory (UMR5240); Bayer CropScience, 14-20 rue Pierre Baizet, F-69263 Lyon cedex, France E-mail: dominique.job@bayercropscience.com Fax: 133-4-72-85-22-97 & 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.proteomics-journal.com Proteomics 2011, 11, 1–12 1 DOI 10.1002/pmic.201000586