铜、镉胁迫对杨树叶片中防御蛋白活性的影响

摘要

In order to determine the potential effect of heavy metals on poplar resistance defense, we analyzed the defensive pro-tein activities in poplar leaves under heavy metal stress at three concentrations of copper ( Cu) ( 400, 700, 1 000 mg/kg) and cadmium (Cd) (1.0, 3.0, 6.0 mg/kg) with one-year poplar potted seedlings. The defensive protein (CAT, SOD, PPO, PAL, CI, TI) activities were impacted by both the concentrations of heavy metals and the treatment time periods. On 30-40 days after the heavy metal stress, at the high concentrations of Cd or Cu, the defensive protein CAT, SOD, PPO, PAL, CI, TI activities were significantly higher than those of the control and peaked on 40th day with low concentra-tions of Cd or Cu, did not result in any changes in the defensive protein activity. However, on 50-60 days after the treat-ments at high concentrations of Cd and Cu, CAT, SOD, PPO, PAL, CI and TI activities were significantly lower than those of the control. While low concentrations of Cd and Cu treatments were still not different from the control treatment, though their activities were the lowest on 60th day.%为明确重金属胁迫对杨树抗性的影响,以1年生杨树扦插盆栽苗为试验材料,分析在重金属铜( Cu)、镉( Cd)胁迫下杨树叶片中防御蛋白活性的变化。分别用Cu、Cd的3种不同质量分数处理扦插盆栽苗的土壤,Cu为400、700、1000 mg·kg-1、Cd为1.0、3.0、6.0 mg·kg-1,30d后开始取样叶分析。结果表明：不同时间段中,防御蛋白CAT、SOD、PPO、PAL、CI、TI活性的变化规律性与重金属质量分数和时间有关,重金属胁迫30~40 d后,高质量浓度Cd、Cu处理样叶中的防御蛋白CAT、SOD、PPO、PAL、CI、TI活性显著高于对照,在第40天时达到最大,低质量分数Cd、Cu处理与对照相比差异不显著；处理50~60 d后,高质量分数Cd、Cu处理样叶中防御蛋白CAT、SOD、PPO、PAL、CI、TI活性显著低于对照,低质量分数Cd、Cu处理与对照相比差异不显著,在第60天的时降到最小。