Most aquatic environments are suffering from microplastic pollution, which poses a threat to the physiological and ecological characteristics of aquatic animals. The phospholipid hydroperoxide glutathione peroxidase gene (PHGPx) has an important function in the antioxidative defense of organisms. Here, we revealed for the first time that the full-length cDNA of PHGPx in Brachionus calyciflorus was 817 bp long and contained a 512 bp open reading frame. B. calyciflorus was exposed to 0 (control), 1 × 10⁴, 1 × 10⁵, 1 × 10⁶, and 1 × 10⁷ particles mL⁻¹ polystyrene (particle size: 1 µm). Specific growth rate (SGR); reproductive rate (R); superoxide dismutase (SOD), catalase (CAT), and PHGPx activities; manganese superoxide dismutase (MnSOD), copper and zinc superoxide dismutase (CuZnSOD), CAT, and PHGPx expression; and reactive oxygen species (ROS) levels were investigated. Our results showed that polystyrene enhanced ROS production. SGR, R, PHGPx activity, and PHGPx expression decreased with the increase in polystyrene concentrations. SOD and CAT activities and MnSOD, CuZnSOD, and CAT expression levels increased upon exposure to 1 × 10⁴–1 × 10⁶ particles mL⁻¹ polystyrene but decreased under exposure to 1 × 10⁷ particles mL⁻¹ polystyrene. These results revealed that PHGPx, MnSOD, CuZnSOD, and CAT expression regulates antioxidant enzyme activities, which are involved in the PHGPx-associated antioxidant defense of rotifers in response to polystyrene.

大多数水生环境都受到微塑料污染，对水生动物的生理和生态特性构成威胁。磷脂氢过氧化物谷胱甘肽过氧化物酶基因（PHGPx）在生物体的抗氧化防御中具有重要功能。在这里，我们发现了第一次的的全长cDNA PHGPx在萼花臂尾为817个碱基组成，包含一个512 bp的开放阅读框。B. calyciflorus暴露于 0（对照）、1 × 10 ⁴、1 × 10 ⁵、1 × 10 ⁶和 1 × 10 ⁷颗粒 mL ^-1聚苯乙烯（粒径：1 µm）。比增长率（SGR）；繁殖率（R）；超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT) 和PHGPx活性；锰超氧化物歧化酶 ( MnSOD )、铜锌超氧化物歧化酶 ( CuZnSOD )、CAT和PHGPx表达；和活性氧 (ROS) 水平进行了研究。我们的结果表明聚苯乙烯增强了 ROS 的产生。SGR、R、PHGPx活性和PHGPx表达随着聚苯乙烯浓度的增加而降低。SOD 和 CAT 活性以及MnSOD、CuZnSOD和CAT表达水平在暴露于 1 × 10 ⁴ –1 × 10 ⁶颗粒 mL ^-1聚苯乙烯时增加，但在暴露于 1 × 10 ⁷颗粒 mL ^-1聚苯乙烯时降低。这些结果表明，PHGPx、MnSOD、CuZnSOD和CAT表达调节抗氧化酶活性，这些活性参与轮虫响应聚苯乙烯的PHGPx相关抗氧化防御。