Universidade Federal do Rio Grande (FURG), Instituto de Ciências Biológicas (ICB), Av. Itália Km 8, Rio Grande, RS, 96203-900, Brazil.
Programa de Pós-Graduação em Biologia de Ambientes Aquáticos Continentais, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, 96203-900, Brazil.
J Plant Res. 2021 May;134(3):577-584. doi: 10.1007/s10265-021-01266-8. Epub 2021 Mar 8.
Glutathione S-transferase (GST) participates in the biotransformation of many xenobiotics including biocides. Its activity in plants is generally associated with their phytoremediation capabilities. Biocides have been used in agriculture and antifouling paints and they represent risks for the aquatic environment. The present study aimed to: (1) evaluate the basal GST activity in roots, stems, and leaves from thirteen plants (eleven aquatic macrophytes and two halophytes) collected at South Brazil wetlands; (2) estimate the biotransformation potential of Nothoscordum gracile for five biocides using competitive kinetic assays with 1-chloro-2,4-dinitrobenzene (CDNB), a typical GST substrate. The N. gracile, Spartina alterniflora and Cakile maritima presented the highest GST activities among the tested plants. The Lineweaver-Burk plot obtained from the GST competitive kinetic assays confirmed that the biocides chlorothalonil, 4,5-dichloro-N-octyl-3(2H)-isothiazolone (DCOIT), dichlofluanid, and diuron, but not irgarol, compete with the substrate CDNB for GST. Chlorothalonil and DCOIT showed the lowest IC values (11.1 and 10.6 μM, respectively), followed by dichlofluanid (38.6 μM) and diuron (353.1 μM). The inhibition of GST-CDNB activity by 100 nM biocide was higher for chlorothalonil, DCOIT, and dichlofluanid (46.5, 49.0, and 45.1%, respectively) than for diuron (6.5%) and irgarol (2.2%). The present study indicates plant species that have significant GST activity and could be potentially used for phytoremediation. The competitive kinetic tests suggest that among the five biocides that were tested, chlorothalonil, DCOIT, and dichlofluanid are probably preferred for biotransformation via GST in plant.
谷胱甘肽 S-转移酶 (GST) 参与许多包括杀生剂在内的异生物质的生物转化。其在植物中的活性通常与其植物修复能力有关。杀生剂曾被用于农业和防污涂料，对水生环境构成风险。本研究旨在：(1) 评估在南巴西南部湿地收集的 13 种植物（11 种水生大型植物和 2 种盐生植物）的根、茎和叶中的基础 GST 活性；(2) 使用竞争性动力学测定法，用典型的 GST 底物 1-氯-2,4-二硝基苯（CDNB）估计 Nothoscordum gracile 对 5 种杀生剂的生物转化潜力。在所测试的植物中，N. gracile、Spartina alterniflora 和 Cakile maritima 的 GST 活性最高。从 GST 竞争性动力学测定中获得的 Lineweaver-Burk 图证实，氯苯腈、4,5-二氯-N-辛基-3(2H)-异噻唑啉酮（DCOIT）、双氯氟脲和敌草隆等杀生剂与 GST 竞争 CDNB。氯苯腈和 DCOIT 的 IC 值最低（分别为 11.1 和 10.6 μM），其次是双氯氟脲（38.6 μM）和敌草隆（353.1 μM）。100 nM 杀生物剂对 GST-CDNB 活性的抑制作用，氯苯腈、DCOIT 和双氯氟脲（分别为 46.5%、49.0%和 45.1%）高于敌草隆（6.5%）和 Irgarol（2.2%）。本研究表明，一些植物物种具有显著的 GST 活性，可能被用于植物修复。竞争动力学试验表明，在所测试的 5 种杀生物剂中，氯苯腈、DCOIT 和双氯氟脲可能是通过植物 GST 进行生物转化的首选。
