Department of Entomology, Iowa State University, Ames, Iowa, USA.
Environ Toxicol Chem. 2011 Mar;30(3):715-22. doi: 10.1002/etc.437. Epub 2011 Jan 19.
Atrazine is a widely used herbicide in agriculture. Non-point source contamination of groundwater and drinking water may pose a significant threat to humans, wildlife, and the environment. Phytoremediation may provide a cost-effective strategy for reducing non-point source contamination of atrazine from agricultural runoff. Previous studies have shown that the rhizosphere of the native prairie grass, switchgrass (Panicum virgatum) is capable of enhancing the degradation of atrazine in soils. Biodegradation also may occur within the plant biomass; however, the extent to which this occurs has not been studied. We hypothesize that switchgrass has the capacity to degrade atrazine in vivo, in addition to the microbial biotransformation that occurs in its rhizosphere. The goals of this study were to characterize the ability of switchgrass to take up atrazine from soils, quantify the amount of biodegradation occurring in the plant, and quantify the amount of degradation occurring in the rhizosphere. Switchgrass seedlings were transplanted into autoclaved and non-autoclaved sand containing 10 µg/g atrazine in sand. Treatments were sacrificed on days 0, 3, and 7. Sand and plant tissue extracts were analyzed by gas chromatography to determine the concentration of atrazine and metabolites in sand and plant tissues. Results demonstrated that leaf biomass is capable of detoxifying atrazine, because metabolites were present in leaf material and not in the sand or root.
莠去津是农业中广泛使用的除草剂。地下水和饮用水的非点源污染可能对人类、野生动物和环境构成重大威胁。植物修复可能为减少农业径流中莠去津的非点源污染提供一种具有成本效益的策略。先前的研究表明，本地草原草柳枝稷（Panicum virgatum）的根际能够增强土壤中莠去津的降解。生物降解也可能发生在植物生物量内；然而，这种情况发生的程度尚未得到研究。我们假设柳枝稷除了在根际发生微生物生物转化外，还有体内降解莠去津的能力。本研究的目的是表征柳枝稷从土壤中吸收莠去津的能力，定量发生在植物体内的生物降解量，并定量根际中的降解量。将柳枝稷幼苗移植到含有 10 µg/g 莠去津的灭菌和未灭菌沙中。在第 0、3 和 7 天处理牺牲。通过气相色谱法分析沙和植物组织提取物，以确定沙和植物组织中莠去津和代谢物的浓度。结果表明，叶片生物量能够解毒莠去津，因为代谢物存在于叶片材料中，而不在沙或根中。
