Activities of antioxidant systems during germination of Chenopodium rubrum seeds

Abstract

The activities of superoxide-dismutase (SOD), catalase (CAT) and peroxidase (POD), and concentrations of glutathione and ascorbate have been studied during the first stages of germination in Chenopodium rubrum L. seeds. The highest CAT and SOD activity was found prior to radicle protrusion, while POD activity was maximal at the time of radicle protrusion and seedling development, new POD isozymes simultaneously appearing. The concentrations of total, reduced and oxidized glutathione showed similar changes during germination, the highest values being detected at the time of radicle protrusion. Ascorbic acid was present in the seeds in a detectable concentration only at the time preceding radicle protrusion, while its oxidized form dehydroascorbic acid was detected during the whole germination period studied. Gibberellic acid (GA3, 160 μM) had no effect on germination percentage, but in presence of GA 3, SOD and CAT activity notably increased prior to radicle protrusion, and oxidized glutathione concentration decreased in further germination.