Acta Entomologica Sinica (2005) 48, 194-202

Hui-Lin Guo and Xi-Wu Gao (2005)
[The mutation of carboxylesterase gene of cotton aphid, Aphis gossypii associated with omethoate resistance]
Acta Entomologica Sinica 48 (2), 194-202
Abstract: A laboratory susceptible strain (YSS) of cotton aphid, Aphis gossypii (Glover), was selected with omethoate in successive generations in the laboratory to develop a resistant strain (YRR ). After 24 generations, the resistance ratio of YRR strain was increased by 124.7-fold compared with the omethoate-susceptible strain. Carboxylesterase activity was significantly lower in the omethoate-resistant strain than in the omethoate-susceptible strain when alpha-naphthyl acetate (alpha-NA)was used as substrate. A carboxylesterase gene had been fully cloned and equenced from both omethoate-susceptible and resistant strains. Comparison of both nucleic acid and deduced amino acid sequences revealed four nucleotide acid differences between the omethoate-susceptible and resistant strain, which resulted in four amino acid substitutions (His¹⁰⁴->Arg, Ala¹²⁸->Val, Thr³³³->Asp, Lys⁴⁸⁴->Arg). Knowledge of the structure of a related enzyme acetylcholinesterase) suggests that one of these substitutions (His¹⁰⁴->Arg) lies within the active site of the enzyme. The GenBank accession numbers of carboxylesterase genes of omethoate-resistant (YRRAA) and susceptible (YSSAA) A. gossypii are AY485216 and AY485214, respectively.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Chinese)
Database assignments for author(s): Xi-Wu Gao

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aphis gossypii