| Abstract Detail
Environmental Physiology Reyna-Llorens, Ivan [1], Cruz-Ortega, Rocio [2], Orozco-Segovia, Alma [2]. The role of oxidative stress during natural priming and germination in Dodonea viscosa (L.) Jacq.-Sapindaceae seeds. Natural priming as a controlled hydration process that occurs prior to germination has been observed to enhance germination rates, synchrony and capacity in seeds under natural conditions; however, the biochemical and molecular aspects have not been studied. In order to define the dynamics of the antioxidant system during the early phases of germination of seeds exposed to natural priming we compared the activity of the main antioxidant enzymes: superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) and ascorbate peroxidase (APX), as well as the levels of reactive oxygen species (ROS), H2O2 and O2- during the first stages of germination (0, 12, 24 and 48h after imbibition) in primed and non-primed seeds. Seeds of Dodonea viscosa were buried in open and closed sites in the slope of the Ajusco Volcano in Mexico City during the dry season, and soil temperature was monitored. Seeds were exhumed when the rainy season was established. Control and buried-seeds were used to test germination and enzyme activity.
Seeds of buried treatments showed a considerable increase in germination rates and synchrony compared with non-primed seeds. In primed-seeds we found a significantly increased in the activity of CAT and SOD compared with control during imbibition times, meanwhile the raise in the levels of H2O2 was significantly more in control than in buried-seeds. Although SOD activity was higher in primed-seeds O2- level didn’t change between treatments. There wasn’t detectable activity for APX in any treatment and the activity of GR was very low and showed no differences between primed and non-primed seeds. These results suggest that seeds under natural priming can prevent oxidative damage through the activation of enzymes of the antioxidant system.
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1 - Universidad Nacional Autonoma de México (UNAM), Instituto de Ecología, Departamento de Ecología Funcional, Circuito Exterior Universitario s/n, Ciudad Universitaria, UNAM, Coyoacan, Mexico, D.F, 04510, Mexico
2 - Universidad Nacional Autonoma de México (UNAM), Instituto de Ecología, Departamento de Ecología Funcional
Keywords:
Natural Priming
oxidative stress
seed germination.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P01010
Abstract ID:310 |
