Abstract: Active oxygen production rate, antioxidant enzyme activity and malondialdehyde (MDA) content were determined for testing the effects of subop timal temperature (18 ℃/10 ℃, day/night) , weak light
(80μmol·m^-2 ·s^-1 ) and salt (70 mmol·L^-1 NaCl) stress on the characteristics of active oxygen metabolism in pepper leaf cells. Significant or extremely significant interaction of subop timal temperature, weak light,and salt stress on the superoxide dismutase ( SOD) , catalase (CAT) , glutathione reductase ( GR) activity were observed during the experiment. Also, at the early stage, there were significant or extremely significant interaction on the activities of ascorbate peroxidase (APX) , glutathione peroxidase (GPX) and the contents of O₂^-, H₂O₂ , similarly, on the content of MDA in late stage. The main effects of salt stress on the APX, CAT activity were higher than that of suboptimal temperature, weak light. The main effects of subop timal temperature were greater to other indexes.

Key words: pepper, suboptimal temperature, weak light, salt stress, active oxygen metabolism