Liman Recep, Ciğerci İbrahim Hakkı, Öztürk Nur Serap
Faculty of Arts and Sciences, Molecular Biology and Genetics Department, Uşak University, Uşak 64300, Turkey.
Faculty of Science and Literatures, Molecular Biology and Genetics Department, Afyon Kocatepe University, Afyonkarahisar 03200, Turkey.
Pestic Biochem Physiol. 2015 Feb;118:38-42. doi: 10.1016/j.pestbp.2014.11.007. Epub 2014 Nov 20.
Imazethapyr (IM) is an imidazolinone herbicide that is currently used for broad-spectrum weed control in soybean and other legume crops. In this study, cytotoxic and genotoxic effects of IM were investigated by using mitotic index (MI), mitotic phases, chromosomal abnormalities (CAs) and DNA damage on the root meristem cells of Allium cepa. In Allium root growth inhibition test, EC50 value was determined as 20 ppm, and 0.5xEC50, EC50 and 2xEC50 concentrations of IM herbicide were introduced to onion tuber roots. Distilled water and methyl methane sulfonate (MMS, 10 mg/L) were used as a negative and positive control, respectively. As A. cepa cell cycle is 24 hours, so, application process was carried out for 24, 48, 72 and 96 hours. All the applied doses decreased MIs compared to control group and these declines were found to be statistically meaningful. Analysis of the chromosomes showed that 10 ppm IM except for 48 h induced CAs but 40 ppm IM except for 72 h decreased CAs. DNA damage was found significantly higher in 20 and 40 ppm of IM compared to the control in comet assay. These results indicated that IM herbicide exhibits cytotoxic activity but not genotoxic activity (except 10 ppm) and induced DNA damage in a dose dependent manner in A. cepa root meristematic cells.
咪草烟（IM）是一种咪唑啉酮类除草剂，目前用于大豆和其他豆类作物的广谱杂草防治。在本研究中，通过使用有丝分裂指数（MI）、有丝分裂阶段、染色体异常（CAs）和DNA损伤，研究了咪草烟对洋葱根尖分生组织细胞的细胞毒性和遗传毒性作用。在洋葱根生长抑制试验中，确定EC50值为20 ppm，并将0.5xEC50、EC50和2xEC50浓度的咪草烟除草剂施用于洋葱块根。蒸馏水和甲基磺酸甲酯（MMS，10 mg/L）分别用作阴性和阳性对照。由于洋葱细胞周期为24小时，因此处理过程进行24、48、72和96小时。与对照组相比，所有施用剂量均降低了有丝分裂指数，且这些下降具有统计学意义。染色体分析表明，除48小时外，10 ppm的咪草烟诱导了染色体异常，但除72小时外，40 ppm的咪草烟降低了染色体异常。在彗星试验中，与对照组相比，20和40 ppm的咪草烟中的DNA损伤明显更高。这些结果表明，咪草烟除草剂在洋葱根尖分生组织细胞中表现出细胞毒性活性，但不具有遗传毒性活性（10 ppm除外），并以剂量依赖方式诱导DNA损伤。
