干旱胁迫下苍术幼苗生理特性变化研究

目的：探讨干旱胁迫下苍术幼苗的生理适应性变化。方法：采用聚乙二醇(PEG-6000)模拟干旱胁迫处理苍术Atractylodes lancea幼苗，检测幼苗体内丙二醛(MDA)含量、可溶性蛋白含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性的动态变化。结果：15%和25%PEG胁迫下，苍术幼苗体内MDA含量随胁迫时间的延长显著增加，且高浓度胁迫下增加幅度较大；可溶性蛋白含量分别于胁迫后3 d和1 d显著提高；SOD，POD，CAT，APX活性表现出先升高后降低的变化趋势，且高浓度变化幅度较大，POD，APX均于胁迫后3 d达到峰值，SOD，CAT活性高峰期根据浓度大小而不一致。结论：干旱胁迫下苍术幼苗可通过提高可溶性蛋白含量来降低水势以适应干旱胁迫；增强抗氧化酶活性，使之相互协调以提高抗氧化能力从而减轻干旱胁迫伤害。

Study on effect of drought stress on physiological adaptation of seedlingsof Atractylodes lancea

Objective: To study the effect of drought stress on the changes of physiological adaptation of Atractylodes lancea seedlings. Method: Investigation was carried out on content changes of MDA, soluble protein, and activities of SOD, POD, CAT, APX in A. lancea seedlings under polyethylene glycol (PEG-6000)-simulated drought stress. Result: In A. lancea seedlings treated with 15% and 25% PEG, the content of MDA increased significantly with the stress time, and increased more significantly at a higher concentration of PEG. The content of soluble protein increased significantly after treatment on the day one and day three; activities of SOD, POD, CAT and APX increased at first and decreased later, increasing rates rose at high concentration of PEG moreover, activities of POD,APX reached the maximum after three days, and the time of maximum activities changed with concentration of PEG. Conclusion: A. lancea seedlings adapted to drought stress by increasing the content of soluble protein to decrease water potential, and by improving activities of protective enzymes to enhance anti-oxidative ability under drought stress.