Direct Conjugation of Emerging Contaminants in Arabidopsis: Indication for an Overlooked Risk in Plants?
Direct Conjugation of Emerging Contaminants in Arabidopsis: Indication for an Overlooked Risk in Plants?
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DOI：
10.1021/acs.est.6b06266
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发表时间：
2017-06-06
影响因子：
11.4
通讯作者：
Gan, Jay
中科院分区：
文献类型：
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作者：
Fu, Qiuguo;Zhang, Jianbo;Gan, Jay
农业使用经过处理的废水、生物固体和动物废物，将多种新兴污染物 (CEC) 引入土壤-植物系统。粮食作物积累 CEC 的潜力很大程度上取决于它们在植物中的代谢，但目前对此知之甚少。在这里）我们评估了萘普生和布洛芬（Profen 家族中两种最常用的人类药物）在拟南芥细胞和拟南芥植物中的代谢。高分辨率质谱和 C-14 标记的互补使用可以对游离和结合代谢物以及不可提取的残留物进行表征。萘普生和布洛芬以其母体形式在拟南芥细胞中快速直接与谷氨酸和谷氨酰胺缀合，并进一步与肽缀合。例如，120小时后，萘普生的代谢物占可提取化学质量的>90%，而完整母体本身可以忽略不计。谷氨酸和谷氨酰胺缀合物的结构得到确认，并在全植物中得到进一步验证。氨基酸缀合物可以很容易地解缀合，释放母体分子。这一发现凸显了此类 CEC 的生物活性可能通过直接缀合有效保留的可能性，这是以前被忽视的风险。许多其他 CEC 也吃羧酸，例如洛芬。因此，直接缀合可能是这些 CEC 的植物代谢的常见途径，因此在评估其风险时必须考虑缀合物。
Agricultural use of treated wastewater, biosolids, and animal wastes introduces a multitude of contaminants of emerging concerns (CECs) into the soil-plant system. The potential for food crops to accumulate CECs depends largely on their metabolism in plants,, which at present is, poorly understood. Here) We evaluated,the metabolism of naproxen,and ibuprofen, two of the most-used human drugs from the Profen family, in Arabidopsis thaliana cells and the Arabidopsis plant. The complementary use of high-resoliition mass specttoinetry and C-14 labeling allowed the characterization of both free and conjugated metabolites, as well as nonextractable residues. Naproxen and ibuprofen, in their parent form, were conjugated quickly and directly with,glutamic acid and glutamine, and further with peptides, in A thaliana cells. For example, after 120 h, the metabolites of :naproxen accounted for >90% of the extractable chemical mass, while the intact parent itself was negligible. The structures of glutamate and glutamine conjugates were confirmed and further verified in whole plants. Amino acid conjugates may easily deconjugate, releasing the parent molecule. This finding highlights the possibility that the bioactivity of such CECs maybe effectively preserved through direct conjugation, a previously overlooked risk. Many other CECs ate also carboxylic adds, such as the profens. Therefore, direct conjugation may be a common route for plant metabolism of these CECs, making it imperative to, consider conjugates when assessing their risks.