晏洪铃　罗琳　李雅贞　罗惠莉　毛石花

摘要：对Zn胁迫下五节芒叶部和根部内过氧化产物丙二醛（MDA）的含量以及多酚氧化酶（PPO）、超氧化物岐化酶（SOD）和过氧化物酶（POD）活性进行了研究。结果表明：叶部和根内MDA活性伴随着Zn胁迫强度的增大而升高，膜脂过氧化水平上升。作为植物抗氧化系统中的关键酶，随着Zn浓度的增加，SOD活性呈现出先上升后下降的两阶段反应，从而说明了Zn的污染超出了植物所能承受的防护阈值，使得其防御能力相应减弱，甚至死亡。PPO活性的下降说明在重金属的伤害下五节芒的抗逆性减弱。而POD活性高于对照说明在重金属胁迫下五节芒植株体内的抗氧化能力增强。由此可见在Zn污染下导致植物被伤害的主要原因是细胞内O2浓度的升高带来的膜脂过氧化水平的增强，而植物体内的保护酶系统SOD、POD和PPO活性的变化则可能是五节芒抗过氧化的机理之一。

关键词：锌；五节芒；酶；抗氧化能力

中图分类号：S 688；X 173文献标识码：A文章编号：1001-005X（2015）01-0001-05

MDA Accumulation and Antioxidation Capacity of

Miscanthus Floridulus Under Zn Stress

Yan Hongling，Luo Lin*，Li Yazhen，Luo Huili，Mao Shihua

（College of Resources and Environment，Hunan Agricultural University，Changsha 410128）

Abstract：The content of peroxidation product malondialdehyde（MDA）and activity of polyphenol oxidase（PPO），superoxide dismutase（SOD）and peroxidase（POD）in the miscanthus leaves and roots under the Zn stress were studied in the paper.The results showed that under the Zn stress，O2 in leaf and root accumulated，and the activity of MDA increased with the increase of Zn stress and a defensive system was started inside the cell with the rising of membrane lipid peroxidation levels.As the key enzyme in the plant antioxidant system，the activity of SOD showed a two stage reaction which increased at first and then decreased as Zn stress increased，which indicated that the stress exceeded the threshold of the plant and its defense diminished correspondingly and even caused the death of the plant.The decrease of the activity of PPO indicated that miscanthus adverse resistance decreased under the pollution of heavy metal.The research showed that activity of POD was higher than the standard value，which means that the antioxidant capacity of miscanthus enhanced under the heavy metal stress.It is concluded that the main reason why the heavy metals are harmful to plants is that membrane lipid peroxidation enhanced due to the increase of O2concentration in the cell under the heavy metal pollution，while the increase of the activity of protective enzyme system SOD and POD is just one of the miscanthus antiperoxidation mechanisms.

Keywords： zinc（Zn）；miscanthus floridulus；enzyme；antioxidation capacity

引文格式：晏洪鈴，罗琳，李雅贞，等.锌污染对五节芒的膜脂过氧化水平及抗氧化能力的影响[J].森林工程，2015，31（1）：1-5.随着全球环境的不断恶化，重金属对土壤和水体的污染问题正得到越来越多的关注[1-2]。Cd，Cu，Zn等重金属对土壤的污染严重破坏了我国的生态环境，阻碍了农业的可持续化发展，同时还可能被作物吸收，通过食物链危及到人类健康[3-4]，因此，研究植株在面对重金属污染下的防御机理，不仅为保持生物多样性，保护生物圈提供了重要的理论基础，也为保持农业安全、优质、高效生产提供了科学的依据[5]。……