Changes of Defense-related Enzyme Activities in TMV-inoculated Tobacco Following High Temperature Stress

By means of temperature shift and artificial inoculation, the change of defense-related enzyme activity in TMV-inoculated tobacco following high temperature stress was determined.The results showed that in TMV-inoculated and high temperature treated (48℃, 24h) tobacco, the activity of superoxide dismutase (SOD) changed a little;catalase (CAT) activity had no obvious change until 48 hours after treating, it began to decrease f rom the third day and increased slightly on the fifth day;the activities of peroxidase (POD) and phenylalanine ammonialyase (PAL) were higher than those in the check; polyphenoloxidase (PPO) activity was higher than that in the check in most stages.Therefore, there is a possible relationship between the change of the activity of CAT, POD, PPO, PAL and the TMV resistance of tobacco induced by high temperature.