铅胁迫对构树幼苗抗氧化酶活性的影响

采用盆栽试验,设置不同铅污染浓度的土壤作为培养基质(100、300、500、700、1 000 mg/kg),研究了铅胁迫对构树一年生幼苗叶片抗氧化酶活性的影响。结果表明:随着培养基质中铅离子浓度增加,构树幼苗叶片中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性呈现出先上升后下降的趋势,过氧化物酶(POD)活性则随铅浓度的升高呈上升的总趋势,且在试验浓度范围内,这3种酶的活性变化与对照组差异均不显著,说明构树对铅离子有较强的耐受性,可作为铅污染地区植被恢复树种。

Effects of Lead Stress on Antioxidant Enzyme Activity of Broussonetia papyrifera Seedlings

Using a potted planting experiment and lead-contaminated soil with different contamination degrees（100,300,500,700,and 1 000 mg/kg）as culture media,the effect of lead stress on antioxidase activity in the annual seedling leaves of Broussonetia papyrifera was studied. The results showed that,along with the increasing in lead ion concentration in culture media,the activities of superoxide dismutase and catalase in Broussonetia papyrifera seedling leaves increased firstly and then decreased,while the activity of peroxidase showed a general increasing trend as the lead concentration increased.Moreover,within the concentration range of the experiments,variations in the activity of these three enzymes were not significantly different compared to that in the control group,indicating that Broussonetia papyrifera had better lead tolerance and could be used as a restoration plant for lead-contaminated regions.