Changes in oxidative stress enzymes during artificial ageing in cotton (Gossypium hirsutum L.) seeds

The present study was carried out to elucidate the mechanism of seed deterioration in two cotton (Gossypium hirsutum L.) cultivars (HS6 and H1098). The seeds were artificially aged at 40 +/- 1 degree C and 100% relative humidity for 4 days. In both cultivars, germinability decreased, whereas membrane deterioration, as assayed by electrical conductivity of the seed leachates, increased progressively with artificial ageing. The decrease in germinability was well correlated with increased accumulation of total peroxide and malondialdehyde content and decreased activities of antioxidant enzymes peroxidase, catalase, ascorbate peroxidase, glutathione reductase and superoxide dismutase. Hydropriming for 2 h and ascorbic acid priming for 12 h partially maintained germination and the activities of various antioxidant enzymes under artificial ageing and the accumulation of peroxide and MDA content was decreased. The results suggest that cotton seed deterioration during accelerated ageing is closely related to a decrease in activities of various peroxide scavenging enzymes and to lipid peroxidation.