苯并三唑对镉在小油菜中的蓄积和毒性的影响

为探讨新型环境污染物苯并三唑(BTR)对重金属镉(Cd)毒性效应的影响,本研究采用水培法对小油菜进行试验,首次系统地探讨了BTR和Cd单独与不同次序联合暴露下小油菜生长状况、抗氧化酶及金属硫蛋白(MT)含量的变化,并分析其毒性作用机理。试验结果表明0.1μmol·L^-1的Cd促进了小油菜的生长,0.5μmol·L^-1以上的Cd抑制了小油菜的生长,且剂量效应显著(R2=0.779);1μmol·L^-1BTR能够显著诱导小油菜SOD酶的表达,但是对其生长基本无影响。Cd与BTR联合暴露下,BTR的加入可以改变Cd的存在形态,降低Cd在小油菜中的蓄积,进而对小油菜生长、抗氧化酶及MT含量变化均产生不同程度的影响,并且降低程度与Cd和BTR的加入先后次序有关。预先暴露BTR能够促进Cd在茎叶中的累积。

Effects of benzotriazole on the uptake and toxicity of cadmium in rapes(Brassica campestris L.)

Rapes(Brassica campestris L.)in hydroponic gardens were tested to investigate the influence of benzotriazole(BTR)on the toxic effect of cadmium(Cd). The changes in growth status, antioxidant enzyme expression, and metallothionein(MT)content of rapes were systematically studied for the first time, and the joint toxicity mechanism was also discussed. The results showed that the growth of rapes could be promoted by Cd at a concentration of 0.1 μmol·L^-1, while it could be inhibited at 0.5 μmol·L^-1 or higher;the dose-effect relationship was significant(R^2=0.779).The expression of the superoxide dismutase(SOD)enzyme in rapes could be significantly induced at a BTR exposure of 1 μmol·L^-1, although there was no effect on the growth of the rapes. The morphology of Cd could be changed and bioaccumulation could be reduced by the combined presence of BTR and Cd, leading to differences in growth status and antioxidant enzyme expression, and MT expressions in rapes. The degree of reduction was related to the exposure sequences of Cd and BTR. When BTR was pre-added in rapes, it could promote the accumulation of Cd in stems.