Liang Jiefeng, Li Yu, Xie Peng, Liu Chunsheng, Yu Liqin, Ma Xufa
College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Environ Sci Pollut Res Int. 2022 Dec;29(58):87717-87729. doi: 10.1007/s11356-022-21785-8. Epub 2022 Jul 11.
In this study, we exposed duckweed (Lemna minor), a floating freshwater plant, to BPA at different concentrations (0, 1, 5, 20, and 50 mg/L) for 7 days so as to investigate the effects of BPA on its growth, photosynthesis, antioxidant system, and osmotic substances. It was found that BPA had the acute toxic effects of "low promotion and high inhibition" on growth and photosynthesis. Specifically, BPA at a low concentration (5 mg/L) significantly promoted the plant growth and improved the concentration of photosynthetic pigments (chlorophyll a, b, and total Chl ) of L. minor. However, BPA at a high concentration (50 mg/L) significantly inhibited the plant growth, the Chl content, and the maximal photochemical efficiency (F/F). Furthermore, BPA with high concentration (50 mg/L) induced ROS accumulation and increased the activities of antioxidant enzymes (SOD, CAT, POD, APX, and GR) and the contents of antioxidant substances (GSH, proline, and T-AOC), which indicated that L. minor might tolerate BPA toxicity by activating an antioxidant defense system. The correlation analysis revealed that the fresh weight of L. minor was significantly and positively correlated with photosynthesis and the contents of soluble protein and sugar, while it was negatively correlated with the content of HO. Totally, these results showed that BPA at different concentrations had dualistic effects on the growth of L. minor, which was attributed to the alterations of photosynthesis, oxidative stress, and osmotic regulation systems and provided a novel insight for studying the effects of BPA on aquatic plant physiology.
在本研究中，我们将漂浮淡水植物浮萍（Lemna minor）暴露于不同浓度（0、1、5、20和50 mg/L）的双酚A（BPA）中7天，以研究BPA对其生长、光合作用、抗氧化系统和渗透物质的影响。结果发现，BPA对生长和光合作用具有“低促高抑”的急性毒性作用。具体而言，低浓度（5 mg/L）的BPA显著促进了植物生长，并提高了浮萍的光合色素（叶绿素a、b和总叶绿素）浓度。然而，高浓度（50 mg/L）的BPA显著抑制了植物生长、叶绿素含量和最大光化学效率（F/F）。此外，高浓度（50 mg/L）的BPA诱导了活性氧（ROS）积累，增加了抗氧化酶（超氧化物歧化酶、过氧化氢酶、过氧化物酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶）的活性以及抗氧化物质（谷胱甘肽、脯氨酸和总抗氧化能力）的含量，这表明浮萍可能通过激活抗氧化防御系统来耐受BPA毒性。相关性分析表明，浮萍的鲜重与光合作用、可溶性蛋白和糖的含量显著正相关，而与过氧化氢含量呈负相关。总的来说，这些结果表明不同浓度的BPA对浮萍的生长具有双重作用，这归因于光合作用、氧化应激和渗透调节系统的改变，为研究BPA对水生植物生理的影响提供了新的见解。
