Institute for Life Sciences and Department of Chemistry, University of Southampton, Southampton, UK.
Biological Sciences, University of Southampton, Southampton, UK.
Pest Manag Sci. 2017 Dec;73(12):2550-2558. doi: 10.1002/ps.4707. Epub 2017 Sep 25.
Macrocyclic lactones are arguably the most successful chemical class with efficacy against parasitic nematodes. Here we investigated the effect of the macrocyclic lactone ivermectin on lipid homeostasis in the plant parasitic nematode Globodera pallida and provide new insight into its mode of action.
A non-invasive, non-destructive, label-free and chemically selective technique called Coherent anti-Stokes Raman scattering (CARS) spectroscopy was used to study lipid stores in G. pallida. We optimised the protocol using the free-living nematode Caenorhabditis elegans and then used CARS to quantify lipid stores in the pre-parasitic, non-feeding J2 stage of G. pallida. This revealed a concentration of lipid stores in the posterior region of J2 s within 24 h of hatching which decreased to undetectable levels over the course of 28 days. We tested the effect of ivermectin on J2 viability and lipid stores. Within 24 h, ivermectin paralysed J2 s. Counterintuitively, over the same time-course ivermectin increased the rate of depletion of J2 lipid, suggesting that in ivermectin-treated J2 s there is a disconnection between the energy requirements for motility and metabolic rate. This decrease in lipid stores would be predicted to negatively impact on J2 infective potential.
These data suggest that the benefit of macrocyclic lactones as seed treatments may be underpinned by a multilevel effect involving both neuromuscular inhibition and acceleration of lipid metabolism. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
大环内酯类化合物无疑是最成功的一类抗寄生线虫化学药物。在这里，我们研究了大环内酯类药物伊维菌素对植物寄生线虫根结线虫脂质稳态的影响，并为其作用模式提供了新的见解。
我们使用一种非侵入性、非破坏性、无标记和化学选择性的技术，称为相干反斯托克斯拉曼散射（CARS）光谱学，来研究根结线虫中的脂质储存。我们使用自由生活的线虫秀丽隐杆线虫优化了该方案，然后使用 CARS 来量化根结线虫 J2 期前、非摄食的 J2 期的脂质储存。结果显示，在孵化后 24 小时内，J2 的后区有浓度的脂质储存，在 28 天的过程中，脂质储存降低到无法检测的水平。我们测试了伊维菌素对 J2 活力和脂质储存的影响。在 24 小时内，伊维菌素使 J2 麻痹。与预期相反的是，在相同的时间过程中，伊维菌素增加了 J2 脂质的消耗速度，这表明在伊维菌素处理的 J2 中，运动和代谢率的能量需求之间存在脱节。这种脂质储存的减少预计会对 J2 的侵染能力产生负面影响。
这些数据表明，大环内酯类化合物作为种子处理的益处可能是由涉及神经肌肉抑制和加速脂质代谢的多层次效应所支撑的。 © 2017 作者。害虫管理科学由 John Wiley & Sons Ltd 代表化学工业协会出版。
