中文摘要：

【目的】研究5-氨基乙酰丙酸（5-aminolevulinic acid,ALA）对中华稻蝗（Oxya chinensis）的杀虫活性及对3种酶活性的影响。【方法】以中华稻蝗4龄若虫为试验材料,用不同剂量的ALA（A1：250mmol·L^-1;A2：450mmol·L^-1;A3：750mmol·L^-1;A4：1000mmol·L^-1）处理中华稻蝗,观察其对中华稻蝗的毒性效应和对其体内乙酰胆碱酯酶（AChE）、谷胱甘肽S-转移酶（GSTs）和谷胱甘肽过氧化物酶（GPx）活性的影响。【结果】不同剂量ALA处理组中华稻蝗死亡率依处理剂量呈现上升趋势,高浓度处理组A3、A4的死亡率分别达到66.19%和80.21%;LD50值为3.61（3.29～3.93）mg·g^-1虫重（95%置信范围）。生化研究结果显示,最高浓度A4处理组雌、雄虫体内AChE活性分别较对照组下降了51.53%和42.65%,差异显著（P〈0.05）;GPx活性分别较对照组下降了42.82%和43.85%,差异显著（P〈0.05）。同时,中华稻蝗GSTs活性随ALA处理剂量升高而增高,A4处理组雌、雄虫体内GSTs活性分别较对照组升高了171.05%及97.42%,差异显著（P〈0.05）。【结论】ALA对雌、雄中华稻蝗均有明显的毒性效应;ALA可引起AChE和GPx光失活,从而导致中华稻蝗神经传导受阻同时抵御氧化损伤的能力下降;高剂量ALA激活GSTs,可引发昆虫对光毒性物质的自身反馈抵御反应。

英文摘要：

[ Objective] Insecticidal activities of 5-aminolevulinic acid （ALA） on Oxya chinensis and the effect on activities of three enzymes were studied. [Method] Fourth-instar nymphs of O. chinensis were treated with different doses of ALA （A1 ： 250 mmol·L^-1; A2：450 mmol·L^-1; A3：750 mmol·L^-1; A4：1 000 mmol·L^-1）. Motality and the activities of acetylcholinesterase （ACHE）, glutathione S-transferase （GSTs） and glutathione peroxidase （GPx） were determinated. [Result] The mortality of O. chinensis increased with increasing dose of ALA. The mortality of high-dose treatments A3 and A4 reached 66.19% and 80.21%, respectively. The value of LD50 was 3.61 （3.29-3.93） mg·g^-1 body weight （95% confidence interval）. Biochemical studies showed that the activities of AChE and GPx in A4 treatment declined by 51.53% and 42.82% in female and 42.65% and 43.85% in male compared to control, respectively, and the degree of decline reached significant level at P〈0.05. Meanwhile, GSTs activities of O. chinensis enhanced with increasing dose of ALA, the GSTs activities of female and male O. chinensis in A4 treatment remarkably increased by 171.05% and 97.42% compared to control （P〈 0.05）. [ Conclusion ] ALA had obviously toxic effect on O. chinensis. Moreover, ALA caused the photoinactivation of AChE and GPx, which induced nerve transmission blocking and the capabilities to defend oxidation damage declining. Meanwhile, high-dose ALA could activate GSTs, which caused a feedback inhibition of insect to the phototoxic substance.