马桑毒素B对粘虫几种生理生化指标的影响

Effect of Tutin on several physiol-biochemical indexes of armyworm

为揭示马桑毒素的杀虫作用机理,对每头4龄粘虫幼虫注射0.5μg马桑毒素B,分析其对粘虫体内谷氨酸(Glu)和γ-氨基丁酸(GABA)的含量及血淋巴含量、比重、酸度、电导率的影响。结果表明,该毒素导致粘虫神经肌肉突触的传导物即兴奋性神经递质Glu下降6%～12%,抑制性神经递质GABA上升14%～400%,GA-BA的相对积累是导致试虫昏迷的直接原因,其作用方式可能相似于苦皮藤 。马桑毒素B同时还导致粘虫血淋巴理化性质产生了变化,干扰了其血淋巴环境中血糖的转化过程,使血液中可溶性营养物质含量减少,血淋巴中水分含量增加,从而引起血淋巴比重下降5.8%;在电导质增加,电导率升高3.47%的同时,改变了血淋巴系统的pH值,使pH升高了0.45%。

To reveal pest control mechanisms of Tutin,this study utilized the injection method and the treatment armyworm larva with 0.5 μg Tutin injection per larva of 4 age.The content of Glu and GABA,content and specific gravity and pH value and conductance ratio of the hemolymph of armyworm larva in vivo,were analysed.The results indicated that the Tutin leaded to the content of excitable neurotransmitter Glu decreasing 6%~12% and repressive neurotransmitter GABA increasing 14%~400%.These two were the neurotransmitter of nerve-muscle synapse.GABAs relative accumulation was the direct reason leading to the coma of test-insect.Pest control mechanisms of Tutin and Celangulin Ⅳ can be similar.Simultaneously,the Tutin leaded to the changes of the physiol-biochem indexes of the hemolymph,disturbed the transformation process of the blood sugar.Content of soluble nutrition substance was decreasing,the water content of the hemolymph increased and the specific gravity decreased 5.8%.When the conductometric substance was increased and the conductance ratio raised 3.47%,pH value of the hemolymph was changed and raised by 0.45%.