title: Catalase is a key enzyme in seed recovery from ageing during priming.
abstract: Ageing induces seed deterioration expressed as the loss of seed vigour and/or viability. Priming treatment, which consists in soaking of seeds in a solution of low water potential, has been shown to reinvigorate aged seeds. We investigate the importance of catalase in oxidation protection during accelerated ageing and repair during subsequent priming treatment of sunflower (Helianthus annuus L.) seeds. Seeds equilibrated to 0.29g H2Og(-1) dry matter (DM) were aged at 35°C for different durations and then primed by incubation for 7 days at 15°C in a solution of polyethylene glycol 8000 at -2MPa. Accelerated ageing affected seed germination and priming treatment reversed partially the ageing effect. The inhibition of catalase by the addition of aminotriazol during priming treatment reduced seed repair indicating that catalase plays a key role in protection and repair systems during ageing. Ageing was associated with H2O2 accumulation as showed by biochemical quantification and CeCl3 staining. Catalase was reduced at the level of gene expression, protein content and affinity. Interestingly, priming induced catalase synthesis by activating expression and translation of the enzyme. Immunocytolocalization of catalase showed that the enzyme co-localized with H2O2 in the cytosol. These results clearly indicate that priming induce the synthesis of catalase which is involved in seed recovery during priming.
authors.affiliation: UR5 EAC7180 CNRS, UPMC Univ. Paris 06, Bat C 2 ème étage, 4, place Jussieu, 75005 Paris, France.
authors.forename: Serge
authors.initials: S
authors.lastname: Kibinza
authors.forename: Jérémie
authors.initials: J
authors.lastname: Bazin
authors.forename: Christophe
authors.initials: C
authors.lastname: Bailly
authors.forename: Jill M
authors.initials: JM
authors.lastname: Farrant
authors.forename: Françoise
authors.initials: F
authors.lastname: Corbineau
authors.forename: Hayat
authors.initials: H
authors.lastname: El-Maarouf-Bouteau
mesh_terms: D002374:Catalase / Q000096:biosynthesis / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D018525:Germination; D006368:Helianthus / Q000201:enzymology / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D012639:Seeds / Q000201:enzymology* / Q000378:metabolism; D013997:Time Factors
chemical_list: D010940:Plant Proteins; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D002374:Catalase