Effects of Different Storage Temperatures and Times on Germination and Antioxidant Responses of Jatropha curcas L. Seeds

Abstract

The effects of different storage temperatures and t imes on germination rate, MalonDiAldehyde (MDA), SuperOxide Dismutase (SOD), PerOxiDase (POD) and Catalase (CAT) activities in Jatropha curcas L. seed were investigated. The results showed that germination rates of seeds stored at room temp erature and 4°C for 1 month was significantly higher than those stored for 3 months at -20 and -80°C. MDA contents increased significantly for 1 and 3 months storage with decreasing temperatures. SOD activity decreased gradually down to -80°C for 1 and 3 months storage. POD activity fluctuated slightly for 1 month, but increased appa rently for 3 months storage with decreasing temperatures. CAT activity declined rapi dly as storage temperatures decreased, particularly for 3 months storage. A sig nificant interaction of storage temperatures and times was found for the activity o f SOD and POD, and there was no significant interaction on germination rate, MDA co ntent, and CAT activity. Electrophoretic analysis showed that the observed c hanges of SOD, POD and CAT isoenzyme bands under different storage temperature s were consistent with the changes of enzyme activities assayed in extract solutions. These results suggested that SOD, POD, and CAT may be involved in regulating the level of reactive oxygen species under different storage temperatures and times. Keywords: Antioxidant enzyme, Germination rate, Isoenzyme pa ttern, Malondialdehyde.