2种新烟碱类杀虫剂对秀丽隐杆线虫神经毒性研究

Neurotoxicity of Two Neonicotinoid Insecticides to Caenorhabditis elegans

新烟碱类(neonicotinoids)是一种类似于烟碱的内吸性杀虫剂,选择性作用于昆虫的中枢神经系统。目前,有关新烟碱类杀虫剂对非靶标生物的生态风险引发了全球的广泛关注。本文采用土壤生物秀丽隐杆线虫(Caenorhabditis elegans)作为受试生物,探究2种新烟碱类杀虫剂吡虫啉(imidacloprid)和呋虫胺(dinotefuran) 24 h暴露(1μg·L^(-1)～10 mg·L^(-1))后,对秀丽线虫运动行为、摄食行为以及乙酰胆碱酶(ACh E)活性和相关基因(ace,mtl)转录水平的影响。结果表明,2种新烟碱类杀虫剂均对秀丽线虫的生理指标具有随着浓度增加而抑制的效应,其中头部摆动是最为敏感的生理指标,10μg·L^(-1)吡虫啉暴露水平和100μg·L^(-1)呋虫胺暴露水平时,线虫头摆频率相较于对照组有显著减少(P <0.01),其次是身体弯曲>摄食>AChE活性(吡虫啉)和摄食>AChE活性>身体弯曲(呋虫胺),相关基因转录水平没有发现与浓度具有相关的效应,但在环境浓度下的暴露有明显的变化。新烟碱类杀虫剂对秀丽线虫的神经毒性作用表明了其对土壤中非靶标生物具有一定的生态风险。

Neonicotinoids are systemic insecticides which have a similar structure with nicotine,acting as agonists of the postsynaptic ligand operated ion channels of the nervous system.Their ecological risk to non-target organisms has raised a great concern in the world.To investigate the adverse effects of two neonicotinoids,i.e.,imidacloprid and dinotefuran,on the soil model organism Caenorhabditis elegans（C.elegans）,locomotion and feeding behavior,acetylcholinase（AChE） activity and related gene expression were evaluated following 24 h exposure to 1 μg·L^-1-10 mg·L^-1.The inhibition in physiological endpoints showed a dose dependent relationship,and the inhibitory effects were stronger with the higher concentration.Among these endpoints,head thrash frequency was the most sensitive one,as the exposure of imidacloprid at 10 μg·L^-1 and dinotefuran at 100 μg·L^-1 caused a significant decrease in head thrash frequency（P〈0.01）,and the following were body bend frequency AChE activity feeding in imidacloprid and AChE activity feeding body bend frequency in dinotefuran.However,the gene expressionvariations scarcely showed a dose dependent relationship,but obviously changed even at an environmental level of concentration exposure.The neurotoxic effects of neonicotinoids on nematode C.elegans show their ecological risk to non-target organisms in the soil.