Toxins 2017, 9(12), 393; https://doi.org/10.3390/toxins9120393
Insight into the Mode of Action of Celangulin V on the Transmembrane Potential of Midgut Cells in Lepidopteran Larvae
1
College of Plant Protection, Northwest A&F University, Yangling 712100, China
2
Provincial Key Laboratory for Botanical Pesticide R&D of Shaanxi, Yangling 712100, China
3
Shandong Institute for Product Quality Inspection, Jinan 250102, China
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These authors contributed equally to this work.
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Author to whom correspondence should be addressed.
Academic Editor: Tomas Girbes
Received: 19 October 2017 / Revised: 28 November 2017 / Accepted: 1 December 2017 / Published: 6 December 2017
(This article belongs to the Section Plant Toxins)
Abstract
Celangulin V (CV) is the main insecticidal constituent of Celastrus angulatus. The V-ATPase H subunit of the midgut cells of lepidopteran larvae is the putative target protein of CV. Here, we compared the effects of CV on the midgut membrane potentials of Mythimna separata and Agrotis ipsilon larvae with those of the Cry1Ab toxin from Bacillus thuringiensis and with those of inactive CV-MIA, a synthetic derivative of CV. We investigated the changes in the apical membrane potentials (Vam) and basolateral membrane potentials (Vbm) of the midguts of sixth-instar larvae force-fed with the test toxins. We also measured the Vam and Vbm of larval midguts that were directly incubated with the test toxins. Similar to the effect of Cry1Ab, the Vam of CV-treated midguts rapidly decayed over time in a dose-dependent manner. By contrast, CV-MIA did not influence Vam. Meanwhile, the Vam of A. ipsilon larval midguts directly incubated with CV decayed less than that of M. separata larval midguts, whereas that of larvae force-fed with CV did not significantly change. Similar to Cry1Ab, CV did not affect the Vbm of isolated midguts. CV significantly inhibited V-ATPase activity in a dose-dependent manner. Therefore, CV initially inhibits V-ATPase in the apical membrane and affects intracellular pH, homeostasis, and nutrient transport mechanisms in lepidopteran midgut cells. View Full-TextKeywords:
Celastrus angulatus; Celangulin V; Mythimna separata; Agrotis ipsilon; midgut apical membrane; transmembrane potential; V-ATPase
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Wang, Y.; Zhang, J.; Feng, M.; Wu, W.; Hu, Z. Insight into the Mode of Action of Celangulin V on the Transmembrane Potential of Midgut Cells in Lepidopteran Larvae. Toxins 2017, 9, 393.
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