铜胁迫对狭叶香蒲生长及生理特性的影响

Effect of Cu2+ stress on the growth and physiological properties of Typha angustifolia

关键词:  狭叶香蒲  Cu2+胁迫  生长  生理特性

Key words:  Typha angustifolia  copper stress  growth  physiological characters

摘要:

采用水培法，研究不同浓度Cu2+胁迫对狭叶香蒲生长及生理特性的影响。结果表明：狭叶香蒲叶宽、株高的增长量及整株干物质累积量在较低浓度Cu2+处理时均未受影响，此后随Cu2+浓度升高显著下降。Cu2+浓度为0～30 mg•L 1时，叶绿素含量显著上升，此后随Cu2+浓度增加其含量显著下降。在Cu2+浓度0～5 mg•L 1范围内根系活力显著上升，此后随Cu2+浓度升高则大幅下降。根系和叶片SOD、POD、CAT活性随Cu2+浓度增加均呈先显著升高后显著降低的趋势，根系SOD、POD活性在30 mg•L 1时出现最大值，叶片SOD、POD活性在55 mg•L 1时出现最大值，根系和叶片CAT活性均在80 mg•L 1时出现最大值；同一Cu2+浓度下，根系SOD、POD、CAT活性明显高于叶片，说明根系比叶片对Cu2+胁迫反应更敏感。从根系和叶片SOD/POD、SOD/CAT的比值变化上看出，在Cu2+为1 mg•L 1和5 mg•L 1时起主要保护作用的酶是SOD、POD，后来CAT起到主要作用。MDA含量自Cu2+浓度为30 mg•L 1时开始持续上升。说明在Cu2+为30～55 mg•L 1时狭叶香蒲表现为积极的生理响应。

Abstract:

Effects of Cu2+ stress on physiological properties and growth of Typha angustifolia were studied by hydroponic culture method. The results showed that the leaf width，plant height and the dry weight accumulation were not obviously affected at the low Cu2+concentration，but decreased with the increasing Cu2+concentration. The content of chlorophyll increased among 0-30 mg•L 1 Cu2+ and decreased obviously with the increasing of Cu2+concentration. Root activity increased among 0-5 mg•L 1 Cu2+ and also decreased apparently afterwards with the increasing of Cu2+concentration.. The activities of SOD，POD and CAT increased with the increasing of Cu2+concentration and decreased clearly afterwards. The highest value of SOD，POD of roots appeared at 30 mg•L 1 Cu2+，while the peak values of in leaves were at 55 mg•L 1 Cu2+. The activity of CAT reached to the highest at 80 mg•L 1. The activities of SOD，POD and CAT of root were higher than leaves apparently under the same Cu2+concentration stress，it was suggested that sensitivity of roots to Cu2+concentrations were higher than that of leaves. The activities of SOD，POD played the main role on protecting T.angustifolia under 1-5 mg•L 1Cu2+ stress，while CAT played the main role afterwards. The content of MDA reached to the high point at 30 mg•L 1 Cu2+ and increased afterwards with the increasing of Cu2+concentration. It was suggested that T.angustifolia had an active physiological response under 30-55 mg•L 1 Cu2+ stress.