School of Environmental and Chemical Engineering, Tianjin Polytechnic University, No. 399 Binshui West Road, Xiqing District, Tianjin 300387, China; Stockbridge School of Agriculture College of Natural Sciences University of Masschusetts, Amherst, USA.
School of Environmental and Chemical Engineering, Tianjin Polytechnic University, No. 399 Binshui West Road, Xiqing District, Tianjin 300387, China.
Chemosphere. 2018 Oct;209:258-267. doi: 10.1016/j.chemosphere.2018.06.090. Epub 2018 Jun 14.
Di(2-ethylhexyl) phthalate (DEHP) is a commonly used, artificially-synthesized, industrial chemical that can be released into the soil. However, to date, there is no comprehensive study on the effects of DEHP on photosynthesis, induction of reactive oxygen species, and response of the antioxidant defense system in wheat plants growing in DEHP contaminated soil. This study was conducted to address this gap in knowledge. Our results showed that after application of 10, 20, and 40 mg/kg DEHP, photosynthetic parameters, fluorescence parameters, and chlorophyll content of wheat leaves at seedling, jointing, and booting stages decreased, while the intercellular carbon dioxide concentration increased. This indicates that the observed decrease in net photosynthetic rate in wheat leaves was due to a non-stomatal limitation, wherein DEHP seems to have hindered the photoelectron transfer process. Both superoxide anion (O) and hydrogen peroxide (HO) content increased in the roots, stems, and leaves in plant under DEHP treatment compared with those in the control plants. Antioxidant enzyme activity increased with increasing DEHP stress, except under the 40 mg/kg treatment at the seedling stage. The antioxidant system had a certain protective effect on wheat, but DEHP still caused peroxidation of cell membrane lipids. The extent of DEHP damage to the roots, stems, and leaves was concentration dependent. Furthermore, enzymatic activity tolerance increased with metabolism, and long-term effects of DEHP gradually decreased with plant growth. Finally, the toxic effects of DEHP on root tissues were more serious at the seedling and jointing stages.
邻苯二甲酸二（2-乙基己基）酯（DEHP）是一种常用的人工合成工业化学品，可能会释放到土壤中。然而，迄今为止，尚无关于 DEHP 污染土壤中生长的小麦植物光合作用、活性氧诱导和抗氧化防御系统响应的综合研究。本研究旨在填补这一知识空白。我们的研究结果表明，施用 10、20 和 40 mg/kg DEHP 后，小麦幼苗、拔节期和孕穗期叶片的光合参数、荧光参数和叶绿素含量降低，而细胞间二氧化碳浓度增加。这表明观察到的小麦叶片净光合速率下降是由于非气孔限制，DEHP 似乎阻碍了光电子传递过程。与对照植株相比，DEHP 处理下植株的根、茎和叶中超氧阴离子（O）和过氧化氢（HO）含量增加。随着 DEHP 胁迫的增加，抗氧化酶活性增加，但在幼苗期 40mg/kg 处理下除外。抗氧化系统对小麦具有一定的保护作用，但 DEHP 仍导致细胞膜脂质过氧化。DEHP 对根、茎和叶的损伤程度与浓度有关。此外，随着代谢，酶活性的耐受性增加，DEHP 的长期影响随着植物生长逐渐降低。最后，DEHP 对根组织的毒性作用在幼苗和拔节期更为严重。
