Key Laboratory of Plant Protection Resources and Pest Management, Ministry of Education, Entomological Museum, College of Plant Protection, Northwest A&F University, Yangling 712100, Shaanxi, China.
J Econ Entomol. 2022 Oct 12;115(5):1551-1556. doi: 10.1093/jee/toac139.
Plutella xylostella (L.) (Lepidoptera: Plutellidae) is one of the most destructive pests of Brassicaceae vegetables. Cantharidin is an insect-derived defensive toxin, which has been reported to have toxicity to a variety of pests and especially lepidopteran pests. Although the toxicity of cantharidin on P. xylostella has been demonstrated, there is little information available on the specific detoxification response of P. xylostella against cantharidin. This study investigates the enzymatic response (including serine/threonine phosphatases [PSPs], carboxylesterases [CarEs], glutathione-S-transferases [GSTs], and cytochrome P450 monooxygenases [P450]) in P. xylostella to the sublethal and low lethal concentrations of cantharidin (LC10 and LC25). Results showed that the inhibitory activity of PSPs was increased and then decreased in vivo, while PSPs activity could be almost completely inhibited in vitro. Interestingly, the activities of detoxification enzymes (GST, CarE, and P450) in P. xylostella displayed a trend of decreasing and then increasing after exposure to the two concentrations of cantharidin. Notably, the increase in P450 enzyme activity was the most significant. The increasing trend of detoxification enzyme activity was congruent with the recovery trend of PSPs activity. This study contributes to our understanding of the detoxification mechanism of cantharidin in P. xylostella and helps in the further development of biogenic agents.
小菜蛾（Lepidoptera: Plutellidae）是十字花科蔬菜的一种极具破坏性的害虫。斑蝥素是一种昆虫来源的防御性毒素，据报道对多种害虫，特别是鳞翅目害虫具有毒性。尽管已证明斑蝥素对小菜蛾具有毒性，但有关小菜蛾对斑蝥素的具体解毒反应的信息却很少。本研究调查了小菜蛾对斑蝥素（LC10 和 LC25）亚致死和低致死浓度的酶反应（包括丝氨酸/苏氨酸磷酸酶[PSPs]、羧酸酯酶[CarEs]、谷胱甘肽-S-转移酶[GSTs]和细胞色素 P450 单加氧酶[P450]）。结果表明，体内 PSPs 的抑制活性先增加后降低，而体外 PSPs 活性几乎可完全被抑制。有趣的是，暴露于两种浓度的斑蝥素后，小菜蛾体内解毒酶（GST、CarE 和 P450）的活性呈现先降低后增加的趋势。值得注意的是，P450 酶活性的增加最为显著。解毒酶活性的增加趋势与 PSPs 活性的恢复趋势一致。本研究有助于我们了解小菜蛾对斑蝥素的解毒机制，并有助于生物制剂的进一步开发。
