Variation in heat stress-induced antioxidant enzyme activities among three mulberry cultivars

The effects of high temperature on antioxidant enzymes were investigatedin three mulberry (Morus alba L.) cultivars (cv. K-2, MR-2and BC2-59). High temperature was imposed by maintaining the plants at 40°Cfor 120, 240 and 360 min in an environmentalplant growth chamber.The activities of superoxide disumutase (SOD), catalase (CAT), guaiacolperoxidase (POD), ascorbate peroxidase (APX) and glutathione reductase (GR)wereassayed in the leaf extracts of control and high temperature-treated plants.Antioxidant enzyme activities were high in all the mulberry cultivars inresponse to high temperature treatment. However, cv. BC2-59 showedsignificantlyhigher activities of all the five antioxidant enzymes in response to hightemperature compared to those from the leaves of K-2, and MR-2 mulberrycultivars. The present study suggested that the cv. BC2-59 has an efficientantioxidant system among the three cultivars, which could prevent the oxidativedamage in the leaves caused by high temperature stress.