环芳烃芘对拟南芥的生物毒性效应

目的]研究多环芳烃（PAHs）对植物生理生化的影响。方法]以模式植物拟南芥为试验材料,研究4环PAHs芘胁迫对拟南芥生长的影响及抗氧化酶活性及叶片超微结构的变化。结果]芘胁迫下拟南芥根长呈现低浓度促进生长、高浓度受抑制的现象,叶片香毛簇随着芘浓度的增加发生畸变。0.25mmol/L的芘胁迫28d后,叶绿素含量显著降低,拟南芥的光合作用过程受到抑制。随胁迫浓度的升高,拟南芥叶片中过氧化物酶（POD）、超氧化物歧化酶（SOD）和抗坏血酸过氧化物酶（APX）的活性显著增强;过氧化氢酶（CAT）的活性先上升后下降,不同浓度芘胁迫下,拟南芥叶片中过氧化氢的平均含量都高于对照。在亚细胞水平上的观察也证实芘处理的拟南芥叶片中叶绿体的数量相对减少,出现肿胀现象,叶肉细胞受到严重损伤,光合作用受阻。结论]该研究可为PAHs对植物的致毒机理以及PAHs污染土壤的植物修复材料筛选提供一些参考。

Bio-toxicity Effect of Polycyclic Aromatic Hydrocarbons Pyrene on Arabidopsis thaliana

Objective] The aim was to study the effects of polycyclic aromatic hydrocarbons(PAHs)pyrene on the physiology and biochemistry of plant.Method] Taking model plant A.thaliana as material,the effects of 4-ring PAHs pyrene stress on A.thaliana growth were studied,as well as the changes of antioxidant enzyme activity and ultrastructure in leaves.Result] Under pyrene stress,the root growth of A.thaliana was enhanced under low concentration but was inhibited under high concentration.Trichomes of A.thaliana leaves distorted with the increase of pyrene concentration.Under 0.25 mmol/L of pyrene stress for 28 d,the photosynthetic process of A.thaliana was inhibited,and chlorophyll content in A.thaliana leaves decreased significantly.With the increase of pyrene concentration,the activity of peroxidase(POD),superoxide dismutase(SOD)and ascorbate peroxidase(APX)in A.thaliana leaves increased significantly,while catalase(CAT)activity went up firstly and then went down.In addition,average H2O2 content in A.thaliana leaves under different pyrene concentrations were higher than that of control.Meanwhile,damaged ultrastructures of few chloroplasts in A.thaliana leaves under pyrene stress were observed,and photosynthesis was inhibited significantly.Conclusion] The study could provide references for the toxic mechanism of PAHs on plant and plant selection in the phytoremediation of PAHs contaminated soil.