Gao Minling, Dong Youming, Zhang Ze, Song Wenhua, Qi Yun
School of Environmental and Chemical Engineering, Tianjin Polytechnic University, No. 399 Binshui Western Road, Xiqing District, Tianjin 300387, China; State Key Laboratory of Separation Membranes and Membrane Processes, Tianjin Polytechnic University, No. 399 Binshui Western Road, Xiqing District, Tianjin 300387, China.
School of Environmental and Chemical Engineering, Tianjin Polytechnic University, No. 399 Binshui Western Road, Xiqing District, Tianjin 300387, China.
Chemosphere. 2017 Apr;172:418-428. doi: 10.1016/j.chemosphere.2017.01.034. Epub 2017 Jan 5.
Phthalate acid esters (PAEs) are vital environmental hormone-like chemicals that are noxious to plants, animals, and human beings. In this study, the influences of di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) on the seed germination, root morphology, and various physiological changes of wheat seedlings were investigated by analyzing superoxide anion (O) accumulation, antioxidant enzyme activity, and lipid peroxidation. DBP and DEHP were found to obviously inhibit germination only at high concentrations, but significantly affected root morphology even at lower concentrations. Their toxic effects were the most severe on root elongation, followed by shoot elongation, and were the least severe on germination rate, indicating that root elongation was the best index for evaluating DBP and DEHP eco-toxicity. DBP and DEHP also enhanced O and malondialdehyde levels and membrane permeability, as well as produced changes in the antioxidant status and PAE content in the stem and leaf (combined tissues, hereafter shoot) and root tissues. The activities of superoxide dismutase, catalase, and peroxidase increased at low and medium DBP and DEHP concentrations, but declined at high PAE concentrations. These results indicated that PAEs could exert oxidative damage in the early development stage of wheat, particularly at higher concentrations. DBP and DEHP accumulation was higher in the roots than in the shoot tissues, and their levels in these tissues increased with increasing PAE concentrations, supporting their more-serious toxic effects on roots than those on shoots. Further, the physicochemical properties of DBP rendered it more harmful than DEHP.
邻苯二甲酸酯（PAEs）是一类重要的环境激素类化学物质，对植物、动物和人类均有害。本研究通过分析超氧阴离子（O）积累、抗氧化酶活性和脂质过氧化作用，研究了邻苯二甲酸二丁酯（DBP）和邻苯二甲酸二（2-乙基己基）酯（DEHP）对小麦种子萌发、根系形态及幼苗各种生理变化的影响。结果发现，DBP和DEHP仅在高浓度时明显抑制种子萌发，但即使在低浓度时也会显著影响根系形态。它们对根伸长的毒性作用最为严重，其次是地上部伸长，对发芽率的毒性作用最小，表明根伸长是评估DBP和DEHP生态毒性的最佳指标。DBP和DEHP还提高了O和丙二醛水平以及膜通透性，并导致茎和叶（以下合并组织为地上部）及根组织中抗氧化状态和PAE含量发生变化。在低、中浓度的DBP和DEHP处理下，超氧化物歧化酶、过氧化氢酶和过氧化物酶的活性增加，但在高PAE浓度下则下降。这些结果表明，PAEs在小麦发育早期可造成氧化损伤，尤其是在较高浓度时。DBP和DEHP在根中的积累高于地上部组织，且这些组织中的含量随PAE浓度的增加而升高，这支持了它们对根的毒性作用比对地上部更严重的观点。此外，DBP的物理化学性质使其比DEHP更具危害性。
