Liu Ying, Ma Li Ya, Lu Yi Chen, Jiang Shuang Shuang, Wu Hong Jin, Yang Hong
Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China.
Jiangsu Key Laboratory of Pesticide Science, College of Science, Nanjing Agricultural University, Nanjing 210095, China; State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing 210095, China.
Ecotoxicol Environ Saf. 2017 Jun;140:264-270. doi: 10.1016/j.ecoenv.2017.02.053. Epub 2017 Mar 8.
Ametryn is a selective herbicide belonging to the triazine family and widely used for killing annual grasses or weeds in China and other parts of the world. However, reports on its environmental risk assessment with regard to soil and crop contamination are limited. In this study, accumulation of ametryn in wheat, maize, ryegrass and alfalfa crops along with ametryn residues in the soil planted with the plants were comparatively investigated. Soil enzyme activities and low molecular weight organic acids (LMWOAs), as well as antioxidant and degradation enzyme activities in plant tissues were measured. The maximum accumulation of ametryn was found in shoots and roots of wheat and alfalfa. Ryegrass had the maximum ametryn translocation factor (TF) from roots to shoots, with more than three times over the other crops. The ametryn residue in ryegrass-planted soil was much lower than that in soil planted with others. The residual content of ametryn in crop-planted soils was ordered as rhizosphere soil<bulk soil<non-rhizosphere soil<control (without plants). Activities of catalase (CAT), glutathione S-transferase (GST) and laccase (LAC) in ametryn-exposed ryegrass were significant higher than those in non-ametryn exposed ryegrass. The maximum activities of CAT in ryegrass shoot and root were increased by 6.16- and 28.84-fold over the control, respectively. Exudation of organic acids in the crop was induced by ametryn and contributed a lot to the degradation of the herbicide. Thus, ryegrass was shown to have a relatively strong ability to remove ametryn from ametryn-contaminated soil and its plant tissues as well.
莠灭净是一种属于三嗪类的选择性除草剂，在中国和世界其他地区广泛用于杀灭一年生禾本科杂草或阔叶杂草。然而，关于其对土壤和作物污染的环境风险评估报告有限。在本研究中，对莠灭净在小麦、玉米、黑麦草和苜蓿作物中的积累以及种植这些作物的土壤中的莠灭净残留进行了比较研究。测定了土壤酶活性和低分子量有机酸（LMWOAs），以及植物组织中的抗氧化酶和降解酶活性。发现莠灭净在小麦和苜蓿的地上部分和根部积累量最大。黑麦草从根部到地上部分的莠灭净转运系数（TF）最大，是其他作物的三倍多。种植黑麦草的土壤中的莠灭净残留量远低于种植其他作物的土壤。种植作物的土壤中莠灭净的残留量顺序为根际土壤<耕层土壤<非根际土壤<对照（无植物）。暴露于莠灭净的黑麦草中过氧化氢酶（CAT）、谷胱甘肽S-转移酶（GST）和漆酶（LAC）的活性显著高于未暴露于莠灭净的黑麦草。黑麦草地上部分和根部CAT的最大活性分别比对照增加了6.16倍和28.84倍。莠灭净诱导了作物中有机酸的分泌，这对除草剂的降解有很大贡献。因此，黑麦草被证明具有较强的从莠灭净污染土壤及其植物组织中去除莠灭净的能力。
