低温胁迫对油桃花器官膜脂过氧化和保护酶活性的影响

低温胁迫下油桃(Amygdalus persicavar.nectariana)花器官不同组织细胞膜透性变化趋势相似,即从缓慢增长到急剧上升之后缓慢上升。MDA含量随着低温胁迫的加剧也表现出相似的变化趋势。花器官不同,膜透性和MDA增加的幅度和临界温度不同。花器官各部分保护酶SOD、POD、CAT和APX活性,在低温胁迫前期均逐渐升高,在达到一定的临界低温后,呈现下降的趋势。这表明花器官内保护酶的存在和活性的提高减轻了由膜脂过氧化引起的伤害,是植物组织提高抗寒性、免遭低温伤害的重要原因。

Effects of chilling stress on membrane lipid peroxidation and activities of protective enzymes in nectarine flower organs

Under low temperature stress, changes of electrolyte leakage percentage of Shuguang nectarine (Amygdalus persica var. nectariana cv. Shuguang) flower organ tissue were similar. The electrolyte leakage percentage increased slowly at early stage, then quickly, and slowly again at the end. The changes of MDA contents had the similar trend as electrolyte leakage percentage along with the severity of low temperature. The range and the critical temperature of membrane lipid penetration and MDA content were various with flower organs. The protective enzyme activity of SOD, POD, CAT and APX in flower organ increased gradually at moderate low temperature stress; then showed declining trend when the temperature attained certain critical temperature. The result showed the existence and enhancement of protective enzymes lightened the damage, which arose by membrane lipid peroxidation;it may be an important reason why plant tissues enhance their chilling resistance and escape low temperature damage.