Altered acetylcholinesterase confers organophosphate resistance in the olive fruit fly Bactrocera oleae

Citation
Jg. Vontas et al., Altered acetylcholinesterase confers organophosphate resistance in the olive fruit fly Bactrocera oleae, PEST BIOCH, 71(2), 2001, pp. 124-132
Citations number
39
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Entomology/Pest Control","Biochemistry & Biophysics
Journal title
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
ISSN journal
0048-3575 → ACNP
Volume
71
Issue
2
Year of publication
2001
Pages
124 - 132
Database
ISI
SICI code
0048-3575(200110)71:2<124:AACORI>2.0.ZU;2-A
Abstract
An organophosphate-resistant strain of the olive fruit fly Bactrocera oleae , the most important pest for olive orchards worldwide, was obtained by lab oratory selection with dimethoate. Resistance mechanisms were investigated in comparison with the colonized parental strain and a field population col lected from the same area after 12 years of continuous dimethoate-based ins ecticide pressure. Combined biochemical and bioassay data suggested that, a lthough esterase and/or glutathione S-transferase metabolic pathways were p resent and active against dimethoate, they were not selected for and did no t have a major role in resistance. There was no evidence of increased oxida se activity in the resistant strains or significant synergism of dimethoate toxicity by piperonyl butoxide; thus, oxidative metabolism was not a major component of resistance. An altered acetylcholinesterase (AChE) with poore r catalytic efficiency for the substrate acetylthiocholine iodide and 5- to 16-fold lower sensitivity to inhibition by omethoate was the major resista nce mechanism. Dimethoate selected the insensitive AChE allele(s) in the re sistant insects, which were also insensitive to paraoxon, but the altered A ChE mechanism conferred negative cross-resistance to the carbamate propoxur . (C) 2001 Academic Press.