难溶态锌、镉对香根草抗氧化酶活性及锌、镉吸收的影响

Effects of Insoluble Zn and Cd on Growth,Activities of Antioxidant Enzymes and Uptake of Zn and Cd in Vetiveria zizanioides

采用土培根袋试验,研究了难溶态锌、镉对香根草生长、抗氧化酶活性、MDA含量及锌、镉吸收累积的影响。结果表明,锌、镉均不同程度抑制了香根草的生长,抑制作用均以锌镉交互>镉>锌。以锌、镉复合污染更加剧了对植物的胁迫。不同生长期(75 d和90 d)锌镉处理的香根草地上部和根系的SOD、POD、CAT活性及MDA含量均显著增加,且随重金属毒性增强,酶活性和MDA含量亦增加。香根草根系膜脂过氧化的程度大于地上部。香根草体内锌镉含量以地上部<根系,但吸收的锌主要富集在地上部,吸收的镉则主要富集在根系,且随着生长期的延长,各锌镉处理的锌镉积累量明显增加。

Pot experiments （root rag method） were carried out to investigate the influence of insoluble Zn, Cd （80 mg/kg Zn, 40 mg/kg Cd, and 80 mg/kg Zn ＋ 40 mg/kg Cd） on the plant growth, activities of antioxidant enzymes, contents of malondialdehyde （MDA） and uptake of Zn and Cd by Vetiveria zizanioides. The results showed that plant growth of Vetiveria zizanioides was inhibited by insoluble Zn and Cd in soil, the toxicity from insoluble Zn and Cd on SDW and RDW of Vetiveria zizanioides was in order of Zn＋Cd 〉 Cd Zn. At 75 d and 90 d, the activities of superoxide dismutase （SOD）, peroxidase （POD） and eatalase （CAT）, and contents of MDA in shoots and roots significantly increased compared to the control, and increased with the increase of the toxicity from insoluble Zn and Cd. The effect of insoluble Zn and Cd on MDA in roots of Vetiveria zizanioides was greater than that in shoots. The concentration of Zn and Cd in shoots was lower than that in roots of Vetiveria zizanioides. The accumulation of Zn was distributed mainly in shoots, while the accumulation of Cd was distributed mainly in roots. The accumulation of Zn and Cd in plants increased with the increase of time.