Abstract: The effects of short time high temperature on the antioxidant enzymes, content of MDA, soluble protein and relative electric conductivity were investigated in Lilium cultivars ('White Heaven'and'Tiber')．The results showed that the changes of plant morphology, relative electric conductivity and MDA content in two cultivars were slightly affected at 37℃ and 42℃ whereas the level of electric conductivity and MDA content increased obviously under 47℃ specially to 'Tiber'. Heat shock could promote the activities of SOD，POD and CAT compared to control and analysis of SOD and POD isoenzymes revealed that the number of SOD isoenzyme was unchanged in two cultivars while the expression of SOD was affected by heat shock.．There were five bands in 'White Heaven' and two bands of POD isoenzyme in'Tiber' were identified．The POD activity for 'White Heaven' was obvious higher than 'Tiber' after heat shock．These results demonstrated that the lily plants might enhance the activities of antioxidant system to alleviate the damage caused by heat stress however the patterns of antioxidant enzymes to response to high temperature of the two cultivars were different.

Key words: Lily, High temperature stress, Antioxidant enzyme, Isoenzyme, MDA, protein