Seed Development and Germination in anArabidopsis thalianaLine Antisense to Glutathione Reductase 2

Abstract

Desiccating and germinating seeds are particularly prone to oxidative stress. Glutathione (GSH) is one of the most abundant and ubiquitous antioxidants in plants. To better understand GSH's role in developing and germinating seeds, wildtype (WT) and a line of seed antisense for glutathione reductase 2 (anGR2), one of two glutathione reductase (GR) genes characterized in the genetic model plant Arabidopsis thaliana, were compared. GSH levels in maturing and germinating seeds were measured by high performance liquid chromatography (HPLC) and GR activity by native Polyacrylamide gel electrophoresis (PAGE). Natural and accelerated aging and germination at high temperature and under water stress were compared for WT and anGR2 seeds. Total GSH pools were two-fold less in anGR2 than in WT after three hours of imbibition. Under high temperature and osmotic stress, germination percentages were lower in anGR2, suggesting a specific relationship between GSH metabolism and stress defense mechanisms early in germinati...