1,2,4-三氯苯对铜钱草染毒的毒性响应及其机理

以水培铜钱草为材料,研究1,2,4-三氯苯(1,2,4-TCB)染毒引起植株叶绿素、类胡萝卜素和可溶性蛋白含量等生理指标的毒性响应,并从叶片丙二醛(MDA)含量及各种抗氧化酶(超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD))的改变探讨了1,2,4-TCB的毒性作用机理.结果表明,1,2,4-TCB(5、10 mg.L-1)处理后,铜钱草叶片各种生理代谢指标与1,2,4-TCB处理之间呈现一定浓度-效应和时间-效应关系,但与对照组间无显著的统计学差异.叶绿素含量、叶绿素a/b和可溶性蛋白均随着1,2,4-TCB处理时间延长先升高后降低;MDA含量随处理时间延长先升高后降低,随浓度增加而增加;SOD和POD活性随处理时间和浓度增加先升高后降低;CAT活性变化不明显.在10 mg.L-11,2,4-TCB处理4—6 d时,各种抗氧化酶活性均达到最大.高浓度1,2,4-TCB(15、20 mg.L-1)处理铜钱草的抗氧化酶活性与对照组相比,均显著降低,且各处理组间也呈现统计学差异.

Toxicity of 1,2,4-trichlorobenzene on Hydrocotyle vulgarisl and its mechanism

A hydroponic experiment was carried out to study the effects of 1,2,4-trichlorobenzene(1,2,4-TCB) on physiological characteristics of Hydrocotyle vulgarisl.The changes of chlorophyll,carotenoid,soluble protein and malondialdehyde(MDA) contents and the activities of antioxidant enzymes such as superoxide dismutase(SOD),catalase(CAT) and peroxidase(POD) were determined.The results showed that the physiological indics of Hydrocotyle vulgarisl changed in a concentration-dependent and time-dependent manner with low concentrations of 1,2,4-TCB(5,10 mg · L-1) treatment,but there was no statistically significant difference between the control group and the treatment group.Total chlorophyll,chlorophyll a/b and soluble proteins all rose first and then fell with treatment time.The content of MDA first increased then decreased with the treatment time,and showed positive correlation with treatment concentration.Activity of SOD and POD first boosted and then declined with treatment time,and the trend with concentration was similar,up first then down.In contrast,activity of CAT changed insignificantly during the experiment.The maximum activity of antioxidant enzymes all reached 10 mg · L-1 during 4—6 d treatment.In high concentration treatment groups(15,20 mg · L-1),activity of every antioxidant enzyme decreased significantly compared to the control,and showed statistical differences among the groups.