干旱胁迫下麻疯树幼苗根和叶的生理应答变化

采用高浓度聚乙二醇胁迫模拟干旱的方法,研究比较了麻疯树幼苗不同组织根和叶对胁迫的应答变化.结果表明,麻疯树幼苗根和叶对胁迫都产生明显应答,二者组织中相对含水量都明显下降,活性氧、可溶性糖、脯氨酸和丙二醛的含量持续增加,抗坏血酸含量呈现先增加后降低的趋势,但同期上述指标变化幅度都不一样.在整个胁迫期间,根和叶的抗氧化酶系统变化不一致,超氧化物歧化酶、过氧化氢酶、过氧化物酶和抗坏血酸还原酶活性的应答启动时间、活性变化幅度和应答持续时间也呈现一定的差异.但是,在整个胁迫处理期,根和叶组织中上述各酶活性均维持高于对照的水平.

Different physiological response to drought stress in root and leaf of seedlings of Jatropha curcas L.

A high concentration of PEG (500 g/L) was used to simulate drought stress for studying the physiological response in root of seedlings of Jatropha curcas. A variety of physiological parameters were monitored in roots of Jatropha curcas. Higher levels of hydrogen peroxide and malondialdehyde were observed in the roots. A significant increase in the contents of soluble sugar and proline was also observed. Along with the stress time increasing, the contents of RWC(relative water content) were decreased. The protect enzyme system all performed complex change, activities of superoxide dismutases (SOD), catalase (CAT), guaiacol peroxidase (POD), ascorbate peroxidase (APX), reduced ascorbate (AsA) in the roots were strongly increased at early stage of PEG stressed, reached the maximum at different time, then were gradually decreased.During the stress time, the activities of SOD,CAT,POD and APX were kept higher level than the control group's