title: Proteomic analysis of seed dormancy in Arabidopsis.
abstract: The mechanisms controlling seed dormancy in Arabidopsis (Arabidopsis thaliana) have been characterized by proteomics using the dormant (D) accession Cvi originating from the Cape Verde Islands. Comparative studies carried out with freshly harvested dormant and after-ripened non-dormant (ND) seeds revealed a specific differential accumulation of 32 proteins. The data suggested that proteins associated with metabolic functions potentially involved in germination can accumulate during after-ripening in the dry state leading to dormancy release. Exogenous application of abscisic acid (ABA) to ND seeds strongly impeded their germination, which physiologically mimicked the behavior of D imbibed seeds. This application resulted in an alteration of the accumulation pattern of 71 proteins. There was a strong down-accumulation of a major part (90%) of these proteins, which were involved mainly in energetic and protein metabolisms. This feature suggested that exogenous ABA triggers proteolytic mechanisms in imbibed seeds. An analysis of de novo protein synthesis by two-dimensional gel electrophoresis in the presence of [(35)S]-methionine disclosed that exogenous ABA does not impede protein biosynthesis during imbibition. Furthermore, imbibed D seeds proved competent for de novo protein synthesis, demonstrating that impediment of protein translation was not the cause of the observed block of seed germination. However, the two-dimensional protein profiles were markedly different from those obtained with the ND seeds imbibed in ABA. Altogether, the data showed that the mechanisms blocking germination of the ND seeds by ABA application are different from those preventing germination of the D seeds imbibed in basal medium.
authors.affiliation: Institut National de la Recherche Agronomique-Institut National Agronomique Paris-Grignon, Chaire de Physiologie Végétale, Unité Mixte de Recherche 204, F-75231 Paris cedex 05, France.
authors.forename: Kamel
authors.initials: K
authors.lastname: Chibani
authors.forename: Sonia
authors.initials: S
authors.lastname: Ali-Rachedi
authors.forename: Claudette
authors.initials: C
authors.lastname: Job
authors.forename: Dominique
authors.initials: D
authors.lastname: Job
authors.forename: Marc
authors.initials: M
authors.lastname: Jullien
authors.forename: Philippe
authors.initials: P
authors.lastname: Grappin
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D017360:Arabidopsis / Q000196:embryology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000187:drug effects / Q000502:physiology; D010937:Plant Growth Regulators / Q000494:pharmacology*; D040901:Proteomics; D012639:Seeds / Q000378:metabolism / Q000502:physiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D000040:Abscisic Acid