Plant accumulation of antibiotic residues presents potential risks to human and ecosystem health. However, the phytometabolic pathways of antibiotics following plant uptake are still largely uncharacterized. This study investigated the phytometabolism of sulfamethazine (SMT) by Arabidopsis thaliana, using 14C-labeled and unlabeled SMT. SMT was accumulated in both roots and shoots of axenic A. thaliana plants (123.7 ± 12.3 and 22.7 ± 1.0 µg/kg fw, respectively) after 21 days of exposure. However, the parent 14C-SMT accounted for only 1.7 ± 0.01% of the total 14C-radioactivity in plant tissues. The majority of 14C-radioactivity taken up by plants was present as bound residues (42.0-68.2% of initially applied 14C-SMT), while extractable 14C-residues accounted for only 7.7-12.6%. A. thaliana metabolized SMT primarily through glycosylation at the N4-nitrogen atom. Additionally, other products, including pterin-SMT, methylsalicylate-SMT, N4-formyl-SMT, desulfo-SMT, hydroxyl-SMT, N4-acetyl-SMT, desamino-SMT, and 2-amino-4,6-dimethylpyrimidine, were also identified. Notably, a portion of the extractable metabolites was excreted into the culture media, requiring characterization of these metabolites as either excreted phytometabolites or abiotic transformation products of SMT based on comparisons between experimental and control reactors.

中文翻译：

---

拟南芥对磺胺二甲嘧啶的吸收，转运和代谢：区分植物代谢产物和培养基中的非生物转化产物。

植物中残留的抗生素会给人类和生态系统健康带来潜在风险。然而，植物吸收后抗生素的植物代谢途径仍未完全表征。这项研究使用14 C标记和未标记的SMT研究拟南芥对磺胺二甲嘧啶（SMT）的植物代谢。暴露21天后，SMT积聚在轴生拟南芥植物的根和芽中（分别为123.7±12.3和22.7±1.0 µg / kg fw）。但是，亲本14C-SMT仅占植物组织中总14C放射性的1.7±0.01％。植物吸收的大部分14C放射性以结合的残基形式存在（占最初应用的14C-SMT的42.0-68.2％），而可提取的14C残基仅占7.7-12.6％。一种。拟南芥主要通过N4-氮原子上的糖基化代谢SMT。另外，其他产品包括蝶呤-SMT，水杨酸甲酯-SMT，N4-甲酰基-SMT，脱硫-SMT，羟基-SMT，N4-乙酰-SMT，脱氨基-SMT和2-氨基-4,6-二甲基嘧啶。也确定了。值得注意的是，一部分可提取代谢物被排入培养基，需要根据实验和对照反应器之间的比较将这些代谢物表征为排泄的植物代谢物或SMT的非生物转化产物。