Effects of High Temperature Stress on Lipid Peroxidation and Protective Enzyme Activity in Sedum Plants

Changes of lipid peroxidation and protective enzyme activity were studied under high temperature stress in five Sedum plants. Five Sedum plants were treated with high temperature of 45 degrees C/30 degrees C (day 13 h/night 11 h) in plant growth chamber, leaves of five plants were chosen for measurement of all physiological indices before stress and each five days after stress to analyze changes of lipid peroxidation and protective enzyme activities.The results showed that with serious level of heat stress for five plants, O-2 (-)production rates and MDA contents increased gradually; activities of SOD, POD, CAT increased at first and then decreased. Sedum plants with stronger heat tolerance had characteristics that O-2(-) production rates increased slowly, MDA contents accumulated slowly and protective enzyme activities enhanced obviously compared with other Sedum plants.