Department of Chemistry, Research Group of Environmental Toxicology, Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 17, 10-720 Olsztyn, Poland.
Department of Chemistry, Research Group of Environmental Toxicology, Faculty of Environmental Management and Agriculture, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 17, 10-720 Olsztyn, Poland.
Aquat Toxicol. 2019 Apr;209:70-80. doi: 10.1016/j.aquatox.2019.01.021. Epub 2019 Jan 25.
Research into plants plays an important role in evaluations of water pollution with pesticides. Lemna minor (common duckweed) is widely used as an indicator organism in environmental risk assessments. The aim of this study was to determine by biological Lemna test and chemical methods the effect of glyphosate (GlyPh) concentrations of 0-40 μM on duckweed, an important link in the food chain. There are no published data on glyphosate's effects on the activity of enzymes of the amine biosynthesis pathway: ornithine decarboxylase, S-adenosylmethionine decarboxylase, tyrosine decarboxylase, lysine decarboxylase and arginine decarboxylase, and the content of shikimic acid and glyphosate residues in the tissues of common duckweed. It was found that glyphosate was taken up by duckweed. In plants exposed to 3 μM of glyphosate for 7 days, glyphosate content exceeded the acceptable Maximum Residue Level (MRL) 10-fold. Glyphosate accumulation in plant tissues exerted toxic effects on duckweed by decreasing its growth and yield, inhibiting the synthesis of chlorophyll a and b and carotenoids, and decreasing the photochemical activity of photosystem II (PSII). However, glyphosate increased the concentration of shikimic acid in the tested plants. The activity of ornithine decarboxylase increased 4-fold in plants exposed to 20 μM of the herbicide. As a water pollutant, glyphosate increased the content of biogenic amines tyramine, putrescine, cadaverine, spermidine and spermine. The activity of peroxidase and catalase was highest in duckweed exposed to 20 μM and 7 μM of the herbicide, respectively. The predicted toxic units were calculated based on glyphosate content and the computed EC values. The mean effective concentration calculated for all morphological and biochemical parameters of duckweed was determined at EC = 1.55, EC = 3.36, EC = 6.62 and EC = 14.08 μM of glyphosate. The study demonstrated that glyphosate, the active ingredient of Roundup Ultra 360 SL herbicide, induces morphological and biochemical changes in non-target plants and exerts toxic effects on aquatic ecosystems even during short-term exposure.
对植物的研究在评估农药水污染方面起着重要作用。浮萍（普通浮萍）被广泛用作环境风险评估中的指示生物。本研究的目的是通过生物浮萍试验和化学方法确定浓度为 0-40 μM 的草甘膦对浮萍的影响，浮萍是食物链中的重要环节。目前还没有关于草甘膦对胺生物合成途径中酶的活性的影响的发表数据：鸟氨酸脱羧酶、S-腺苷甲硫氨酸脱羧酶、酪氨酸脱羧酶、赖氨酸脱羧酶和精氨酸脱羧酶，以及组织中的莽草酸和草甘膦残留量普通浮萍。结果发现浮萍吸收了草甘膦。在暴露于 3 μM 草甘膦 7 天的植物中，草甘膦含量超过可接受的最大残留限量（MRL）10 倍。草甘膦在植物组织中的积累通过降低其生长和产量、抑制叶绿素 a 和 b 以及类胡萝卜素的合成以及降低光系统 II（PSII）的光化学活性，对浮萍产生了毒性作用。然而，草甘膦增加了测试植物中的莽草酸浓度。暴露于除草剂 20 μM 的植物中鸟氨酸脱羧酶的活性增加了 4 倍。作为一种水污染物质，草甘膦增加了生物胺酪胺、腐胺、尸胺、亚精胺和精胺的含量。暴露于 20 μM 和 7 μM 除草剂的浮萍中过氧化物酶和过氧化氢酶的活性最高。基于草甘膦含量和计算出的 EC 值，计算了预测的毒性单位。根据草甘膦含量和所有形态和生化参数计算出的有效浓度，确定了浮萍的 EC=1.55、EC=3.36、EC=6.62 和 EC=14.08 μM。研究表明，草甘膦，即 Roundup Ultra 360 SL 除草剂的有效成分，会引起非靶标植物的形态和生化变化，并在短期暴露期间对水生生态系统产生毒性作用。
