背景:植物具有许多防御性次生代谢产物以抵御昆虫攻击。史帕龙,从药用植物蒿中提取,对朱砂四虫具有有效的杀螨作用。螺双氯芬,衍生自四烯酸衍生物,是一种有效的商业杀螨剂,在全球广泛使用。然而,与螺氯芬联合使用时,scoparone是否具有协同作用以及潜在的协同机制尚不清楚.
结果:当将其与螺双氯芬以1:9的比例组合时,Scoparone表现出有效的协同作用。随后,细胞色素P450单加氧酶(P450)活性,RNA-Seq和qPCR检测表明,P450的酶活性和一个P450基因的表达。TcCYP388A1被soparone和螺氯芬+soparone显著抑制;相反,P450在暴露于螺氯芬的螨中被激活。重要的是,RNAi介导的TcCYP388A1基因沉默显着增加了蜘蛛螨对螺双氯芬的易感性,scoparone和螺氯芬+scoparone,在体外,重组TcCYP388A1蛋白可以代谢螺氯芬。分子对接和功能分析进一步表明,R117在蛛形纲物种中高度保守,可能是螨TcCYP388A1蛋白中soparone的重要特异性结合位点。随后使用诱变数据确认了该结合位点,这表明该结合位点是scoparone在哺乳动物或苍蝇CYP388A1上的蜘蛛螨中选择的唯一位点。
结论:这些结果表明,scoparone和螺氯芬对螨虫的协同作用是通过抑制P450活性发生的,从而减少螺氯芬的代谢。这种有效的天然产物对商业杀螨剂的解毒酶靶向活性的协同作用可能为害虫螨抗性管理提供可持续的策略。©2024化学工业学会。
BACKGROUND: Plants have numerous defensive secondary metabolites to withstand insect attacks. Scoparone, which is extracted from the medicinal plant Artemisia capillaris, has potent acaricidal effects on Tetranychus cinnabarinus.
Spirodiclofen, derived from a tetronic acid derivative, is a potent commercial acaricide that is extensively used globally. However, whether scoparone has synergistic effects when used in conjunction with
spirodiclofen and the underlying synergistic mechanism remains unclear.
RESULTS: Scoparone exhibited a potent synergistic effect when it was combined with spirodiclofen at a 1:9 ratio. Subsequently, cytochrome P450 monooxygenase (P450) activity, RNA-Seq and qPCR assays indicated that the enzyme activity of P450 and the expression of one P450 gene from T. cinnabarinus, TcCYP388A1, were significantly inhibited by scoparone and spirodiclofen + scoparone; conversely, P450 was activated in
spirodiclofen-exposed mites. Importantly, RNAi-mediated silencing of the TcCYP388A1 gene markedly increased the susceptibility of spider mites to spirodiclofen, scoparone and spirodiclofen + scoparone, and in vitro, the recombinant TcCYP388A1 protein could metabolize
spirodiclofen. Molecular docking and functional analyses further indicated that R117, which is highly conserved in Arachnoidea species, may be a vital specific binding site for scoparone in the mite TcCYP388A1 protein. This binding site was subsequently confirmed using mutagenesis data, which revealed that this binding site was the sole site selected by scoparone in spider mites over mammalian or fly CYP388A1.
CONCLUSIONS: These results indicate that the synergistic effects of scoparone and spirodiclofen on mites occurs through the inhibition of P450 activity, thus reducing
spirodiclofen metabolism. The synergistic effect of this potent natural product on the detoxification enzyme-targeted activity of commercial acaricides may offer a sustainable strategy for pest mite resistance management. © 2024 Society of Chemical Industry.