水分和铅交互胁迫对侧柏幼苗抗氧化酶活性的影响

Effects of interactive stress of dought and lead on antioxidant enzyme activity of Platycladus orientalisseedlings

通过盆栽实验研究一年生侧柏(Platycladus orientalis)在不同水分处理(土壤相对含水率为40%、60%、80%、100%)及重金属铅五个胁迫水平(0、300、500、1000、2000mg·kg-1)交互作用下抗氧化酶活性(POD、SOD)和丙二醛(MDA)含量的变化。结果表明:在水分和铅的交互胁迫下,侧柏幼苗叶片POD、SOD活性均表现为先升后降的趋势,不同水分胁迫条件下侧柏幼苗叶片POD、SOD活性均在铅含量为500mg·kg-1时达到最大值,在铅含量<500mg·kg-1时,不同水分胁迫条件下侧柏幼苗叶片POD、SOD活性都随着铅胁迫的增大逐渐上升,在铅含量>500mg·kg-1时,不同水分胁迫条件下侧柏幼苗叶片POD、SOD活性都随着铅胁迫的增大逐渐下降。在水分和铅的交互胁迫下,侧柏幼苗叶片MDA含量逐渐升高,在铅含量<1000mg·kg-1时,不同水分胁迫条件下侧柏幼苗叶片MDA含量变化不明显,在铅含量>1000mg·kg-1时,不同水分胁迫条件下侧柏幼苗叶片MDA含量逐渐上升。适当的交互胁迫(铅含量500mg·kg-1,60%水分处理)有利于提高侧柏的抗逆性。

This research is aimed at MDA content in one year seedlings exploring the theory of the changes of antioxidant enzyme system activity and of Platycladus orientalis treated by different levels of water （ 40%, 60%, 80%, and 100% ） and lead （ 0, 300, 500, 1 000, and 2 000rag .kg-1 ） and cuhivated in pots. The results showed that POD, SOD activities of Platycladus orientalis seedlings increased at first and then decreased under interactive stress, POD, SOD activities of Platycladus orientalis seedlings treated by different levels of water reach maximum in the lead content of 500mg . kg- 1 , under lead less than 500mg . kg- l, POD, SOD activities of Platycladus orientalis seedlings increased in different water stress conditions, under lead more than 500mg . kg-1, POD, SOD activities of Platycladus orientalis seedlings decreased in different water stress conditions. MDA content of Platycladus orientalis seedlings increased 1000mg - kg-1, MDA content of Platycladus orientalis stress conditions, under lead more than 1000mg . kg-1 gradually under interactive stress, under lead less than seedlings showed no obvious change in different water , MDA content of Platycladus orientalis seedlings in- creased gradually under interactive stress. Platycladus orientalis showed stronger resistance in the interaction stress of drought and lead （500mg .kg-1 lead stress and 60% water stress）.