害虫拒食行为调控物质的筛选模型研究

STUDIES ON ANTIFEEDING MECHANISM AND ELECTROPHYSIOLOGICAL METHOD AS A BIOASSAY MODEL WITH LARVAL OF -OSTRINIA FURNACALIS- GUENEE

以亚洲玉米螟 (Ostrinia furnacalis)幼虫为试材 ,以电生理技术顶端记录法 ,确定栓锥感受器是拒食活性的靶标器官 ,建立拒食活性物质规范化的筛选模型 ,作为检测合成或半合成的克罗烷二萜类化合物的拒食活性。结果表明 :既可抑制其糖电位诱发侧栓锥感受器的脉冲频率 ,亦可直接诱发中栓锥感受器特定细胞引起的脉冲频率变化 ,且与拒食行为生测法的结果基本吻合 ,成正相关。利用离体的味觉感受靶标器官的电生理方法 ,可以定性或定量检测拒食活性 ,研究构效关系 ,具有快速、灵敏。

Toosendanin, Plumbagin and 25 Clerodanes were first tested for their antifeeding activities against the fifth instar larvae of -Ostrinia furnacalis.- Sensory disrupting experiments pointed the maxillary styloconic sensilla to be the target sites of antifeedants. Further electrophysiological studies with tip-recording mode showed that antifeedants could both reduce impulse frequency of lateral styloconic sensillae evoked by sugar and produce particular impulses at medial styloconic sensillae. Moreover, taking all the chemicals into account, impulse frequencies at medial styloconic sensillae and antifeeding rates in behavior test exhibited prominent positive correlation suggesting that sensory activity explained well for the behavior response and electrophysiological method might be applied in detection of antifeedants as a screening model to quickly assess the potential behavioural effect of a compound using minute amounts of test material.