title: Dynamics of the antioxidant system during seed osmopriming, post-priming germination, and seedling establishment in Spinach (Spinacia oleracea).
abstract: Osmopriming is a pre-sowing treatment that improves seed germination performance and stress tolerance. To understand osmopriming physiology, and its association with post-priming stress tolerance, we investigated the antioxidant system dynamics during three stages: during osmopriming, post-priming germination, and seedling establishment. Spinach seeds (Spinacia oleracea L. cv. Bloomsdale) were primed with -0.6 MPa PEG at 15°C for 8 d, and dried at room temperature for 2 d. Unprimed and primed germinating seeds/seedlings were subjected to a chilling and desiccation stresses. Seed/seedling samples were collected for antioxidant assays and germination performance and stress tolerance were evaluated. Our data indicate that: (1) during osmopriming the transition of seeds from dry to germinating state represses the antioxidant pathways (residing in dry seeds) that involve CAT and SOD enzymes but stimulates another pathway (only detectable in imbibed seeds) involving APX; (2) a renewal of antioxidant system, possibly required by seedling establishment, occurs after roughly 5 d of germination; (3) osmopriming strengthens the antioxidant system and increases seed germination potential, resulting in an increased stress tolerance in germinating seeds. Osmopriming-mediated promotive effect on stress tolerance, however, may diminish in relatively older (e.g. ~5-week) seedlings.
authors.affiliation: Department of Horticulture, Iowa State University, 139 Horticulture Hall, Ames, IA 50011-1100, USA.
authors.forename: Keting
authors.initials: K
authors.lastname: Chen
authors.forename: Rajeev
authors.initials: R
authors.lastname: Arora
mesh_terms: D000222:Adaptation, Physiological; D000975:Antioxidants / Q000378:metabolism*; D060387:Ascorbate Peroxidases / Q000378:metabolism; D001205:Ascorbic Acid / Q000032:analysis; D002374:Catalase / Q000378:metabolism; D003080:Cold Temperature; D055864:Droughts; D018525:Germination / Q000187:drug effects / Q000502:physiology*; D005978:Glutathione / Q000032:analysis; D008315:Malondialdehyde / Q000032:analysis; D009994:Osmolar Concentration; D018384:Oxidative Stress / Q000502:physiology; D010940:Plant Proteins / Q000378:metabolism; D011092:Polyethylene Glycols / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000502:physiology; D012639:Seeds / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000502:physiology; D018724:Spinacia oleracea / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors
chemical_list: D000975:Antioxidants; D010940:Plant Proteins; D017382:Reactive Oxygen Species; D011092:Polyethylene Glycols; D008315:Malondialdehyde; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione; D001205:Ascorbic Acid