The involvement of microsomal oxidases in pyrethroid resistance in Helicoverpa armigera from Asia

Yang, Yihua; Wu, Yi; Chen, S.; Devine, Gregor J.; Denholm, I.; Jewess, P. J.; Moores, G. D.

doi:10.1016/j.ibmb.2004.04.001

Cited by 133 publications

(98 citation statements)

References 45 publications

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“…Clearly PBO does inhibit some esterases under certain conditions in vitro and synergises some resistances in vivo in which P450s and esterases are both involved. We also note the synergism of Cry1Ac resistance by the PBO analogue EN16/6 as reported by Gunning et al 69) On the other hand there are cases such as the SP resistance in Chinese H. armigera where Yang et al 54) found synergism ratios for DEF and PBO that were quite precisely multiplicative and predictive of the overall resistance of the study population. These results would imply that the two synergists are acting independently, on different mechanisms, at least in this case.…”

Section: Discussionsupporting

confidence: 81%

“…[56][57][58] Whether this geographic variation in the strength of the associations reflects genetic differences among populations or methodological differences among investigators is moot, although some effect of genetic differences seems likely. Esterases seem to be responsible for only a few-fold resistance in Chinese populations, 54,55) whereas much higher resistance factors have been attributed to the esterases in some of the other populations. 39,42) Similarly the increase in esterase activity in the Chinese resistant strains is only a few-fold but in at least one Australian study the corresponding figure is reported to be as much as 50-fold.…”

Section: Heliothine Resistance To Spsmentioning

confidence: 96%

“…39,42) Similarly the increase in esterase activity in the Chinese resistant strains is only a few-fold but in at least one Australian study the corresponding figure is reported to be as much as 50-fold. 40,54) Significantly, the correlation between esterase activity and the degree of resistance was shown to hold up when an Indian population was selected for increased SP resistance in the laboratory: esterase activity increased in parallel with resistance over the course of selection. 51) Some authors have also suggested that the role of the esterases relative to P450s may have been underestimated in the (many) cases where a contribution from P450s to the resistance has been inferred from synergism data with the P450 inhibitor PBO.…”

Section: Heliothine Resistance To Spsmentioning

confidence: 99%

“…The association is particularly strong in data for populations from Australia, [39][40][41][42] south and southeast Asia [43][44][45][46][47][48][49][50][51] and central Africa 52,53) and is also significant in Chinese populations, 46,54,55) although it has not been found in west African populations. [56][57][58] Whether this geographic variation in the strength of the associations reflects genetic differences among populations or methodological differences among investigators is moot, although some effect of genetic differences seems likely.…”

Section: Heliothine Resistance To Spsmentioning

confidence: 99%

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Esterase-based metabolic resistance to insecticides in heliothine and spodopteran pests

Farnsworth

Teese

Yuan

et al. 2010

Journal of Pesticide Science

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IntroductionCarboxylesterases have been implicated in metabolic resistance to several classes of insecticide in a wide variety of pest insect species. [1][2][3] The classes most commonly involved are synthetic pyrethroids (SPs) and organophosphates (OPs), and carbamates (CBs) are also involved in several cases. There are also occasional reports of carboxylesterase phenotypes associated with resistance to benzoylureas, the oxadiazine indoxacarb, the diacylhydrazine tebufenozide, the organochlorine endosulfan and the proteinaceous Cry1Ac toxin of Bacillus thuringiensis that is expressed in transgenic crops. Figure 1 gives structures for some key compounds among these various classes of insecticide.It might be expected that carboxylesterases would be involved in SP resistance because the great majority of SPs are carboxylesters. However, no precise molecular mechanisms for esterase-based SP resistance have yet been elucidated in any insect. OPs are generally phosphotriesters rather than carboxylesters but nevertheless they bind many carboxylesterases with high affinity and this provides a basis for two forms of resistance, both now elucidated at a molecular level in several species. One form involves substantial overexpression of the esterase, allowing for effective sequestration of the insecticide. The other involves specific mutations in the active site of the enzyme which convert it to an OP hydrolase (the so-called "mutant ali-esterase" mechanism). CBs are carbamic acid (NH 2 COOH) derivatives, in which a functional group has been added as an ester; these esters are chemically similar to carboxylesters. Carbamates bind carboxylesterases with quite high affinity, but as yet the molecular mechanisms by which a (mutant) carboxylesterase confers CB resistance have not been elucidated in any species. Of the other insecticide classes occasionally linked to esterase-based resistance only indoxacarb has ester bonds (two Elevated esterase activities and increased band intensities of multiple esterase isozymes after electrophoresis are commonly associated with resistance to organophosphate, pyrethroid and carbamate insecticides in various heliothine and spodopteran pests. One possible explanation for this involves a 'master regulator' mutation in a more general chemical stress response. An association between elevated esterase activities and isozyme intensities has also been reported for resistance to the Cry1Ac toxin of Helicoverpa armigera. The basis for this is unclear albeit some involvement of esterases could be mediated by the toxin's affinity for N-acetyl galactosamine glycans on certain gut-expressed esterases in this species.

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Section: Discussionsupporting

confidence: 81%

Section: Heliothine Resistance To Spsmentioning

confidence: 96%

Section: Heliothine Resistance To Spsmentioning

confidence: 99%

Section: Heliothine Resistance To Spsmentioning

confidence: 99%

See 2 more Smart Citations

Esterase-based metabolic resistance to insecticides in heliothine and spodopteran pests

Farnsworth

Teese

Yuan

et al. 2010

Journal of Pesticide Science

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“…This confirms the hypothesis that somes esterases, GSTs, and cytochrome P450 enzymes may be insensitive to the action of DEF and Pb. The involvement of EST and the GST in the OPs resistance was confirmed by many previous studies [2,3,[25][26][27][28][29][30][31][32]. Our study is in agreement with previous publication on correlation between cytochrome P450 enzymes and resistance to pyrethroids [33].…”

Section: Discussionsupporting

confidence: 93%

Study on Resistance of Culex pipiens (Diptera: Culicidae) Populations to Fenitrothion in Northern Tunisia

Tabbabi¹,

Daaboub²,

Cheikh³

et al. 2017

Hereditary Genet

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Four populations of Culex pipiens were collected as larvae in Northern Tunisia to evaluate their resistance status against two insecticides: fenitrothion and propoxur. At LC50, the sample # 1 was susceptible, whereas all the other samples were resistant. The RR50 ranged from 1.08 in sample # 1 to 550 in sample # 3. The A2-B2, A4-B4 (and/or A5-B5), B12 and C1 esterases were found in collected samples and the frequencies ranged from 0.02 to 0.42. Propoxur caused a mortality of 0% in samples # 3 which showed the highest resistance levels to fenitrothion insecticide and 87% in sample # 1 which was susceptible hence the involvement of AChE 1 in the recorded resistance. Our results are essential for the development of such strategies of vector control.

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MOLECULAR CHARACTERIZATIONS OF TWO CYTOCHROME P450 GENES ENCODING CYP6A41 AND CYP6EK1 FROM THE ORIENTAL FRUIT FLY, Bactrocera dorsalis (DIPTERA: TEPHRITIDAE)

Huang

Jiang

Shen

et al. 2012

Arch Insect Biochem Physiol

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Two P450 genes encoding CYP6A41 and CYP6EK1 were cloned from the oriental fruit fly using polymerase chain reaction (PCR) and rapid amplification of cDNA ends (RACE) techniques. CYP6A41 and CYP6EK1 contained open reading frames of 1,530 and 1,524 nucleotides that encode 510 and 508 amino acid residues, respectively. The putative proteins shared 44% identity with each other. Phylogenetic analysis showed that CYP6A41 and CYP6EK1 were most closely related to Ceratitis capitata CYP6A10 and CYP6A subfamily. Expression patterns of the two genes in different geographical populations (Yunnan, Hainan, Dongguang, and Guangzhou), developmental stages (eggs, larvae, pupae, and adults), and tissues (midguts, fat bodies, and Malpighian tubules) were analyzed by real-time quantitative PCR (RT-qPCR) methods. The results showed that the expression levels of CYP6EK1 were significantly different among the four populations, but were not different for CYP6A41. Both the expressions of CYP6A41 and CYP6EK1 were development specific and had significantly higher levels in the larval stage. The expression of CYP6A41 did not vary among the midgut, fat body, or Malpighian tubules; however, CYP6EK1 expression was higher in the Malpighian tubules. The results suggest that CYP6A41 and CYP6EK1 might be involved in detoxification of xenobiotic compounds that were harmful to larval flies or development. Moreover, high expression of CYP6EK1 in the Malpighian tubules also implied participation in detoxification.

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The involvement of microsomal oxidases in pyrethroid resistance in Helicoverpa armigera from Asia

Cited by 133 publications

References 45 publications

Esterase-based metabolic resistance to insecticides in heliothine and spodopteran pests

Esterase-based metabolic resistance to insecticides in heliothine and spodopteran pests

Study on Resistance of Culex pipiens (Diptera: Culicidae) Populations to Fenitrothion in Northern Tunisia

MOLECULAR CHARACTERIZATIONS OF TWO CYTOCHROME P450 GENES ENCODING CYP6A41 AND CYP6EK1 FROM THE ORIENTAL FRUIT FLY, Bactrocera dorsalis (DIPTERA: TEPHRITIDAE)

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