title: Redox-sensitive proteome and antioxidant strategies in wheat seed dormancy control.
abstract: Oxidative signalling by ROS has been demonstrated to play a role in seed dormancy alleviation, but the detailed molecular mechanisms underlying this process remain largely unknown. Here, we show dynamic differences in redox-sensitive proteome upon wheat seed dormancy release. Using thiol-specific fluorescent labelling, solubility-based protein fractionation, 2-D IEF PAGE, and MS analysis in conjunction with wheat EST sequence libraries, proteins with reversible oxidoreductive changes were characterized. Altogether, 193 reactive Cys were found in 79 unique proteins responding differentially in dormant, non-dormant, abscisic, or gibberellic acid-treated seed protein extracts from RL4137, a wheat cultivar with extreme dormancy. The identified proteins included groups that are redox-, stress-, and pathogen-responsive, involved in protein synthesis and storage, are enzymes of carbohydrate metabolism, proteases, and those involved in transport and signal transduction. Two types of redox response could be detected: (i) a dramatic increase in protein thiol redox state in seeds during imbibition and hormonal treatment; (ii) higher antioxidant capacity related to sensing of a threshold redox potential and balancing the existing redox pools, in dry dormant versus non-dormant seeds. These results highlight occurrence of the antioxidant defence mechanisms required for the protection of seed during a dormancy stage.
authors.affiliation: Cereal Research Centre, Agriculture and Agri-Food Canada, Winnipeg, MB, Canada. nbykova@mun.ca
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Bykova
authors.forename: Brenda
authors.initials: B
authors.lastname: Hoehn
authors.forename: Christof
authors.initials: C
authors.lastname: Rampitsch
authors.forename: Travis
authors.initials: T
authors.lastname: Banks
authors.forename: Jo-Ann
authors.initials: JA
authors.lastname: Stebbing
authors.forename: Tao
authors.initials: T
authors.lastname: Fan
authors.forename: Ron
authors.initials: R
authors.lastname: Knox
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D020224:Expressed Sequence Tags; D015723:Gene Library; D018525:Germination / Q000187:drug effects / Q000502:physiology; D005875:Gibberellins / Q000494:pharmacology; D007525:Isoelectric Focusing; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000502:physiology; D057445:Plant Dormancy / Q000187:drug effects / Q000235:genetics; D010937:Plant Growth Regulators / Q000494:pharmacology; D010940:Plant Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D020543:Proteome / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013050:Spectrometry, Fluorescence; D013438:Sulfhydryl Compounds / Q000378:metabolism; D014908:Triticum / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
chemical_list: D005875:Gibberellins; D010937:Plant Growth Regulators; D010940:Plant Proteins; D020543:Proteome; D017382:Reactive Oxygen Species; D013438:Sulfhydryl Compounds; D000040:Abscisic Acid; C007842:gibberellic acid