高温和干旱胁迫对2种景天植物膜脂过氧化及保护酶活性的影响

EFFECTS OF HIGH TEMPERATURE AND DROUGHT STRESS ON LIPID PEROXIDATION AND PROTECTIVE ENZYME ACTIVITIES IN TWO Sedum PLANTS

试验研究了德景天和红花德景天在高温及干旱双重胁迫下膜脂过氧化及保护酶活性的变化。结果表明:随着胁迫程度加重,2种景天的O2-·产生速率持续升高,MDA含量先升后降,H2O2含量先降低后上升,但总体上积累;对高温干旱适应性强的德景天O2-·产生速率上升慢、MDA含量积累少。胁迫过程中,2种景天的POD、SOD、CAT酶活性呈先升高后降低的趋势,对高温干旱适应性强的德景天3种酶活性增幅高;胁迫结束时3种酶活性均高于胁迫前,说明高温干旱胁迫诱导2种景天植物3种保护酶活性增强,通过增强保护酶活性来降低膜脂过氧化程度。

This experiment was studied on lipid peroxidation and protective enzyme activities of Sedum hybridum and Sedum hybridum ＇ Immeryrunchett＇ under high temperature and drought stress. Results showed that ： As the stress increasing, O2 - · production rates of two Sedum. plants increased persistently, MDA contents of two Sedum. plants decreased after the first rise , H2O2 contents de- creased and then increased , while H2O2 contents were at situation of accumulation at whole process;O2 - · production rates of Se- dum hybridum which was better adaptability to high temperature and drought stress increased slowly and MDA contents accumulated less. In the process of stress, the enzyme activities of POD ,SOD ,CAT increased in the early and then decreased, Three enzyme ac- tivities were all higher than that before stress and 3 enzyme activities of Sedum hybridum which was better adaptability to high temper- ature and drought stress increased. More, this stated that stress induced higher activities of three enzymes to reduce level of mem- brane lipid peroxidation in two Sedum. plants.