铜、锌胁迫对丁香蓼生理指标的影响

Effects of Cu and Zn stress on physiological indications of Ludwigia prostrate Roxb

通过盆栽实验研究了铜、锌单一及复合胁迫时对丁香蓼(Ludwigia prostrateRoxb)叶片叶绿素含量和活性氧清除系统的影响。结果表明:较低质量分数铜(100 mg/kg)、锌(100 mg/kg)处理时,叶绿素含量上升,SOD活性增加,电导率、MDA水平则下降,可认为这是植物的一种保护性机制。但随着铜、锌处理质量分数的增大,SOD活性下降,800 mg/kg铜、锌处理下丁香蓼SOD活性分别是对照的67.05%和53.58%;POD活性则逐渐增加,起主要抗氧化作用,其中以铜(200 mg/kg)+锌和锌(200 mg/kg)+铜两个处理系列变幅最大;MDA含量随处理质量分数的增加而增加,其中200 mg/kg铜+800 mg/kg锌和200 mg/kg锌+800 mg/kg铜处理时,MDA分别高出对照110%和130%;CAT活性持续下降,但在此过程中作用不明显。因此,铜、锌胁迫明显地影响活性氧清除系统,导致丁香蓼叶片活性氧代谢失调。

Effects of single and combined stress of Cu and Zn on chlorophyll content and scavenging system of activated oxygen in leaves of Ludwigia prostrate Roxb were studied by cultivation experiments. The results showed that the activity of SOD and contents of chlorophyll increased firstly in lower concentration of Cu （ 100 mg/kg） and Zn （ 100 mg/kg）. At the same time, electric conductivity and MDA content of leaf ceils decreased. Those may be regarded as a protecting function of plants. With the increase of concentration of Cu and Zn, the activity of SOD decreased. When the concentration of Cu ＆ Zn was 800 mg/kg, the activity of SOD were 67.05% and 53.58% of the control, respectively. While the activity of POD increased gradually and took important parts in antioxidation at higher concentration of Cu and Zn stress. The content of MDA of Cu （200 mg/kg） ＋ Zn （800 mg/kg） ＆ Zn （200 mg/kg） ＋ Cu （800 mg/kg） was enhanced with Cu, Zn concentration increasing. Compared with the control they were increased by 110% and 130% , respectively. The activity of CAT had little effect. The results indicated that Cu and Zn stress affected scavenging system of activated oxygen and resulted in imbalance of activated oxygen metabolism.