Institute of Pesticide Science, Northwest Agriculture and Forestry University, Yangling 712100, China.
Toxins (Basel). 2014 May 14;6(5):1575-85. doi: 10.3390/toxins6051575.
Periplocoside NW (PSNW) is a novel insecticidal compound isolated from the root bark of Periploca sepium Bunge and has potent stomach toxicity against some insect pests. Previous studies showed that the Mythimna separata larva is sensitive to PSNW, but the Agrotis ispilon larva is insensitive. In this study, preliminary target localization on the midgut of M. separata larvae was conducted via a fluorescence labeling technique. A comparative ultrastructural study on the effects of PSNW on the midguts of M. separata and A. ispilon larvae was performed. Symptom observation results showed that typical stomach toxicity was induced by PSNW in M. separata larvae. Fluorescence localization results showed that PSNW binds to the midgut cells of M. separata larvae. Ultrastructure observations showed destruction of the microvilli, organelle, and cytomembrane in the midgut cells of M. separata larvae, whereas no obvious changes were observed in midgut cells of A. ispilon larvae. These results were consistent with the insecticidal activity of PSNW. Therefore, PSNW might act on the midgut tissues of the insects, and one or more binding sites of PSNW may exist in M. separata larvae midgut cell cytomembranes.
杠柳毒苷 NW（PSNW）是从杠柳根皮中分离得到的一种新型杀虫剂化合物，对一些害虫具有强烈的胃毒性。先前的研究表明，粘虫幼虫对 PSNW 敏感，而斜纹夜蛾幼虫不敏感。在这项研究中，通过荧光标记技术对粘虫幼虫中肠进行了初步的靶标定位。对 PSNW 对粘虫和斜纹夜蛾幼虫中肠的影响进行了比较超微结构研究。症状观察结果表明，PSNW 对粘虫幼虫诱导了典型的胃毒性。荧光定位结果表明，PSNW 与粘虫幼虫的中肠细胞结合。超微结构观察显示，粘虫幼虫中肠细胞的微绒毛、细胞器和细胞内膜遭到破坏，而斜纹夜蛾幼虫中肠细胞没有明显变化。这些结果与 PSNW 的杀虫活性一致。因此，PSNW 可能作用于昆虫的中肠组织，并且 PSNW 在粘虫幼虫中肠细胞质膜上可能存在一个或多个结合位点。
