Zhang Faming, Sun Shixian, Rong Yuhong, Mao Lili, Yang Shuchun, Qian Ling, Li Rongbiao, Zheng Yi
Faculty of Plant Protection, Yunnan Agricultural University, Kunming, 650201, People's Republic of China.
Yunnan Key Laboratory of Plateau Wetland Conservation, Restoration and Ecological Services, Kunming, 650224, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Mar;30(15):44415-44429. doi: 10.1007/s11356-023-25395-w. Epub 2023 Jan 24.
The intensive and long-term use of atrazine (ATZ) has led to the contamination of agricultural soils and non-target organisms, posing a series of threats to human health through the transmission of the food chain. In this study, a 60-day greenhouse pot experiment was carried out to explore the phytoremediation by Chrysopogon zizanioides L. (vetiver). The uptake, accumulation, distribution, and removal of ATZ were investigated, and the degradation mechanisms were elucidated. The results showed that the growth of vetiver was inhibited in the first 10 days of the incubation; subsequently, the plant recovered rapidly with time going. Vetiver grass was capable of taking up ATZ from the soil, with root concentration factor ranging from 2.36 to 15.55, and translocating to the shoots, with shoot concentration factor ranging from 7.51 to 17.52. The dissipation of ATZ in the rhizosphere soil (97.51%) was significantly higher than that in the vetiver-unplanted soil (85.14%) at day 60. Metabolites were identified as hydroxyatrazine (HA), deethylatrazine (DEA), deisopropylatrazine (DIA), and didealkylatrazine (DDA) in the samples of the shoots and roots of vetiver as well as the soils treated with ATZ. HA, DEA, DIA, and DDA were reported first time as metabolites of ATZ in shoots and roots of vetiver grown in soil. The presence of vetiver changed the formation and distribution of the dealkylated products in the rhizosphere soil, which remarkably enhanced the occurrence of DEA, DIA, and DDA. Arthrobacter, Bradyrhizobium, Nocardioides, and Rhodococcus were the major atrazine-degrading bacterial genera, which might be responsible for ATZ degradation in the rhizosphere soil. Our findings suggested that vetiver grass can significantly promote ATZ degradation in the soil, and it could be a strategy for remediation of the atrazine-contaminated agricultural soil.
长期大量使用莠去津（ATZ）已导致农业土壤和非靶标生物受到污染，通过食物链传递对人类健康构成一系列威胁。本研究进行了为期60天的温室盆栽试验，以探究香根草对莠去津的植物修复作用。研究了香根草对莠去津的吸收、积累、分布和去除情况，并阐明了其降解机制。结果表明，在培养的前10天香根草的生长受到抑制；随后，随着时间推移植物迅速恢复。香根草能够从土壤中吸收莠去津，根富集系数在2.36至15.55之间，并向地上部分转运，地上部分富集系数在7.51至17.52之间。在第60天时，根际土壤中莠去津的消散率（97.51%）显著高于未种植香根草的土壤（85.14%）。在香根草地上部和根部样品以及用莠去津处理过的土壤中，鉴定出的代谢产物有羟基莠去津（HA）、脱乙基莠去津（DEA）、脱异丙基莠去津（DIA）和双脱烷基莠去津（DDA）。HA、DEA、DIA和DDA首次被报道为生长在土壤中的香根草地上部和根部中莠去津的代谢产物。香根草的存在改变了根际土壤中脱烷基产物的形成和分布，显著增加了DEA、DIA和DDA的生成量。节杆菌属、慢生根瘤菌属、诺卡氏菌属和红球菌属是主要的莠去津降解细菌属，可能是根际土壤中莠去津降解的原因。我们的研究结果表明，香根草能显著促进土壤中莠去津的降解，可作为修复受莠去津污染的农业土壤的一种策略。
