ABSTRACT Organophosphorus pesticides, one of the most extensively used organic chemicals to control several insect pests, making them threaten the aquatic creatures. Here, we analysed the response mechanism of Nitzschia palea to insecticides (acephate and trichlorfon) exposure, through physiological, biochemical, morphological changes and the removal ability. Results showed that the growth of N. palea was inhibited by trichlorfon, with the cell density was significantly decreased at 7 days of exposure. Although the diatom growth was hardly inhibited after acephate treatment, the diatom valve significantly abnormal morphology be found at 50 mg L−1 acephate treatment after 7 days. Meanwhile, these insecticides had no negative effect on the chlorophyll a content of N. palea. In addition, acephate and trichlorfon induced the activities of superoxide dismutase (SOD) and catalase (CAT) in the diatom, which play a defensive role against various environmental stresses. For further analysis revealed that the content of malondialdehyde (MDA) and extracellular polysaccharides (EPS) increased on exposure to both insecticides. N. palea also promoted 24.44–32.75% removal of acephate. The biochemical changes in N. palea on exposure to acephate and trichlorfon indicate that the diatom undergoes an adaptive change in response to the insecticides-induced oxidative stress.

中文翻译：

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淡水硅藻 Nitzschia palea 对两种有机磷农药的生理反应及去除能力

摘要 有机磷农药是控制多种害虫的最广泛使用的有机化学品之一，使它们威胁到水生生物。在此，我们从生理、生化、形态变化和去除能力等方面分析了尼氏对杀虫剂（乙酰甲胺磷和敌百虫）暴露的响应机制。结果表明，敌百虫抑制了苍蝇的生长，暴露7天时细胞密度显着降低。虽然高甲磷处理后硅藻生长几乎没有受到抑制，但在50 mg L-1 高甲磷处理7天后，发现硅藻瓣形态明显异常。同时，这些杀虫剂对N.palea的叶绿素a含量没有负面影响。此外，乙酰甲胺磷和敌百虫诱导硅藻中超氧化物歧化酶 (SOD) 和过氧化氢酶 (CAT) 的活性，对各种环境胁迫起到防御作用。进一步分析表明，暴露于两种杀虫剂后，丙二醛 (MDA) 和细胞外多糖 (EPS) 的含量增加。N.palea 还促进了 24.44-32.75% 的乙酰甲胺磷去除率。暴露于乙酰甲胺磷和敌百虫的 N.palea 中的生化变化表明，硅藻在响应杀虫剂引起的氧化应激时发生了适应性变化。Palea 还促进了 24.44-32.75% 的乙酰甲胺磷去除率。暴露于乙酰甲胺磷和敌百虫的 N.palea 中的生化变化表明，硅藻在响应杀虫剂引起的氧化应激时发生了适应性变化。Palea 还促进了 24.44-32.75% 的乙酰甲胺磷去除率。暴露于乙酰甲胺磷和敌百虫的 N.palea 中的生化变化表明，硅藻在响应杀虫剂引起的氧化应激时发生了适应性变化。