Age-specific expression of a P450 monooxygenase (CYP6CM1) correlates with neonicotinoid resistance in Bemisia tabaci
Age-specific expression of a P450 monooxygenase (CYP6CM1) correlates with neonicotinoid resistance in Bemisia tabaci
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DOI：
10.1016/j.pestbp.2011.07.004
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发表时间：
2011-09-01
影响因子：
4.7
通讯作者：
Denholm, Ian
中科院分区：
文献类型：
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作者：
Jones, Christopher M.;Daniels, Miriam;Denholm, Ian
粉虱（半翅目：粉虱科）是世界范围内危害农业和园艺的一种入侵害虫。新烟碱类杀虫剂以突触后神经膜上的烟碱乙酰胆碱受体为靶点，在控制烟粉虱方面发挥着重要作用，尽管对这些化合物的抗药性日益增加，正在削弱它们的有效性。新烟碱抗性已被证明是由细胞色素p450依赖的单加氧酶基因CYP6CM1上调引起的，该基因参与杀虫剂解毒。本研究的主要目的是进一步研究烟粉虱对新烟碱类吡虫啉的抗性在很大程度上局限于成虫，而未成熟期则保留敏感性。首先利用生物测定、生化和分子技术鉴定了4株烟粉虱（B型和q型）对吡虫啉的抗性。然后建立了相对基因表达测定法来测量白色成虫、蛹和若虫中CYP6CM1的mRNA水平。我们发现CYP6CM1的表达与每个菌株的成虫和若虫的年龄特异性吡虫啉抗性相关。此外，通过液相色谱-质谱（LC-MS）测定，该基因的上调与吡虫啉代谢为羟基代谢物有关。这些发现加强了CYP6CM1对吡虫啉解毒的参与，并表明CYP6CM1的转录变化可能受到P450酶在昆虫发育中的作用的限制，是烟粉虱年龄特异性抗性表型的原因。(C) 2011爱思唯尔公司版权所有。
The whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), is an invasive insect pest of agriculture and horticulture worldwide. The neonicotinoid insecticides, which target nicotinic acetylcholine receptors in post-synaptic nerve membranes, play a major role in controlling B. tabaci although the increasing incidence of resistance to these compounds is now undermining their effectiveness. Neonicotinoid resistance has been shown to be caused by up-regulation of a cytochrome P450-dependent monooxygenase gene, CYP6CM1, involved in insecticide detoxification. The main aim of this study was to further investigate the finding that expression of resistance to the neonicotinoid imidacloprid is largely restricted to adults of B. tabaci, whereas immature stages retain susceptibility. Imidacloprid resistance was first characterised in four strains of B. tabaci (B- and Q-biotypes) using bioassays, biochemical and molecular-based techniques. A relative gene expression assay was then developed to measure mRNA levels of CYP6CM1 in whitely adults, pupae and nymphs. We show that CYP6CM1 expression correlated with age-specific imidacloprid resistance in adults and nymphs from each strain. Furthermore, in adult whiteflies, the up-regulation of this gene was correlated with imidacloprid metabolism into a hydroxy metabolite as determined by liquid chromatography-mass spectrometry (LC-MS). These findings strengthen the involvement of CYP6CM1 imidacloprid detoxification and suggest that transcriptional changes in CYP6CM1, possibly constrained by the role of P450 enzymes in insect development, are the cause of an age-specific resistance phenotype in B. tabaci. (C) 2011 Elsevier Inc. All rights reserved.