Contamination of fluoroquinolones (FQs) are of emerging concerns because of their adverse effects on environment and humans. This study investigated the ecotoxicological effects, biodegradation, and multiple metabolic pathways of a frequently found FQ, enrofloxacin (ENR) by ryegrass (Lolium perenne L.). Key metabolic genes for driving the metabolism of ENR have been identified using transcriptome profiling of L. perenne and gene network analysis. Toxicity of ENR on ryegrass has been evaluated according to the morphological changes, lipid peroxidation content, and antioxidant enzymatic activities. Moreover, there was 94.33%, 71.58%, 57.22%, and 55.23% removal of 1, 10, 50 and 100 mg L⁻¹ ENR, respectively, which was mainly achieved by biodegradation according to the mass balance. A biodegradation pathway has been proposed by incorporating mass spectrums of extracted ENR intermediates with their formation dynamics. Analysis of differentially expressed genes (DEGs) and their network unraveled that the genes encoding monooxygenase, oxidative carboxylase, methyltransferase, lyase, hydroxylase, dehydrogenase, and peroxidase were the key functional genes. These enzymes can induce di/hydroxylation, decarboxylation, methylation, and bond and ring cleavage of ENR for its effective degradation. This study demonstrated that ryegrass can be used for efficient treatment of ENR polluted water and extended the understanding of the molecular mechanism of antibiotics’ biodegradation in plants.

由于氟喹诺酮类药物 (FQ) 对环境和人类的不利影响，它们的污染成为新出现的问题。本研究调查了黑麦草 ( Lolium perenne L.) 中常见的 FQ 恩诺沙星 (ENR) 的生态毒理学效应、生物降解和多种代谢途径。已经使用多年生黑麦草的转录组分析和基因网络分析确定了驱动 ENR 代谢的关键代谢基因。已经根据形态变化、脂质过氧化含量和抗氧化酶活性评估了 ENR 对黑麦草的毒性。此外，1、10、50 和 100 mg L ^{-1 的}去除率分别为 94.33%、71.58%、57.22% 和 55.23%ENR，分别是根据质量平衡主要通过生物降解来实现的。通过将提取的 ENR 中间体的质谱与其形成动力学相结合，提出了一种生物降解途径。对差异表达基因 (DEG) 及其网络的分析表明，编码单加氧酶、氧化羧化酶、甲基转移酶、裂解酶、羟化酶、脱氢酶和过氧化物酶的基因是关键的功能基因。这些酶可以诱导 ENR 的二/羟基化、脱羧、甲基化以及键和环裂解，以使其有效降解。该研究表明黑麦草可用于有效处理 ENR 污染水，并扩展了对抗生素在植物中生物降解的分子机制的理解。