School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai, 201418, China.
Los Angeles Regional Water Quality Control Board, Los Angeles, CA, 90013, USA.
Environ Sci Pollut Res Int. 2024 Apr;31(19):28754-28763. doi: 10.1007/s11356-024-32927-5. Epub 2024 Apr 1.
Fenoxaprop-p-ethyl (FE) is one of the typical aryloxyphenoxypropionate herbicides. FE has been widely applied in agriculture in recent years. Human health and aquatic ecosystems are threatened by the cyanobacteria blooms caused by Microcystis aeruginosa, which is one of the most common cyanobacteria responsible for freshwater blooming. Few studies have been reported on the physiological effects of FE on M. aeruginosa. This study analyzed the growth curves, the contents of chlorophyll a and protein, the oxidative stress, and the microcystin-LR (MC-LR) levels of M. aeruginosa exposed to various FE concentrations (i.e., 0, 0.5, 1, 2, and 5 mg/L). FE was observed to stimulate the cell density, chlorophyll a content, and protein content of M. aeruginosa at 0.5- and 1-mg/L FE concentrations but inhibit them at 2 and 5 mg/L FE concentrations. The superoxide dismutase and catalase activities were enhanced and the malondialdehyde concentration was increased by FE. The intracellular (intra-) and extracellular (extra-) MC-LR contents were also affected by FE. The expression levels of photosynthesis-related genes psbD1, psaB, and rbcL varied in response to FE exposure. Moreover, the expressions of microcystin synthase-related genes mcyA and mcyD and microcystin transportation-related gene mcyH were significantly inhibited by the treatment with 2 and 5 mg/L FE concentrations. These results might be helpful in evaluating the ecotoxicity of FE and guiding the rational application of herbicides in modern agriculture.
精恶唑禾草灵（FE）是典型的苯氧羧酸类除草剂之一。近年来，FE 在农业中得到了广泛应用。由铜绿微囊藻引起的水华藻会威胁到人类健康和水生生态系统，铜绿微囊藻是造成淡水水华的最常见蓝藻之一。目前，关于 FE 对铜绿微囊藻的生理影响的研究较少。本研究分析了不同 FE 浓度（即 0、0.5、1、2 和 5 mg/L）暴露下铜绿微囊藻的生长曲线、叶绿素 a 和蛋白质含量、氧化应激和微囊藻毒素-LR（MC-LR）水平。结果表明，FE 在 0.5 和 1 mg/L FE 浓度下刺激铜绿微囊藻的细胞密度、叶绿素 a 含量和蛋白质含量，但在 2 和 5 mg/L FE 浓度下抑制其生长。FE 还增强了超氧化物歧化酶和过氧化氢酶的活性，增加了丙二醛的浓度。FE 还影响了细胞内（intra-）和细胞外（extra-）MC-LR 的含量。FE 暴露还影响了与光合作用相关的基因 psbD1、psaB 和 rbcL 的表达水平。此外，2 和 5 mg/L FE 浓度处理显著抑制了微囊藻毒素合成相关基因 mcyA 和 mcyD 以及微囊藻毒素转运相关基因 mcyH 的表达。这些结果可能有助于评估 FE 的生态毒性，并指导现代农业中除草剂的合理应用。
