Enhanced activity of carbohydrate- and lipid-metabolizing enzymes in insecticide-resistant populations of the maize weevil, Sitophilus zeamais

dc.creatorAraújo, R.A.
dc.creatorGuedes, R.N.C.
dc.creatorOliveira, M.G.A.
dc.creatorFerreira, G.H.
dc.date2018-04-24T17:16:28Z
dc.date2018-04-24T17:16:28Z
dc.date2007-11-01
dc.date.accessioned2023-09-27T21:51:23Z
dc.date.available2023-09-27T21:51:23Z
dc.identifier14752670
dc.identifierhttps://doi.org/10.1017/S0007485308005737
dc.identifierhttp://www.locus.ufv.br/handle/123456789/19092
dc.identifier.urihttps://repositorioslatinoamericanos.uchile.cl/handle/2250/8967153
dc.descriptionInsecticide resistance is frequently associated with fitness disadvantages in the absence of insecticides. However, intense past selection with insecticides may allow the evolution of fitness modifier alleles that mitigate the cost of insecticide resistance and their consequent fitness disadvantages. Populations of Sitophilus zeamais with different levels of susceptibility to insecticides show differences in the accumulation and mobilization of energy reserves. These differences may allow S. zeamais to better withstand toxic compounds without reducing the beetles' reproductive fitness. Enzymatic assays with carbohydrate- and lipid-metabolizing enzymes were, therefore, carried out to test this hypothesis. Activity levels of trehalase, glycogen phosphorylase, lipase, glycosidase and amylase were determined in two insecticide-resistant populations showing (resistant cost) or not showing (resistant no-cost) associated fitness cost, and in an insecticide-susceptible population. Respirometry bioassays were also carried out with these weevil populations. The resistant no-cost population showed significantly higher body mass and respiration rate than the other two populations, which were similar. No significant differences in glycogen phosphorylase and glycosidase were observed among the populations. Among the enzymes studied, trehalase and lipase showed higher activity in the resistant cost population. The results obtained in the assays with amylase also indicate significant differences in activity among the populations, but with higher activity in the resistant no-cost population. The inverse activity trends of lipases and amylases in both resistant populations, one showing fitness disadvantage without insecticide exposure and the other not showing it, may underlay the mitigation of insecticide resistance physiological costs observed in the resistant no-cost population. The higher amylase activity observed in the resistant no-cost population may favor energy storage, preventing potential trade-offs between insecticide resistance mechanisms and basic physiological processes in this population, unlike what seems to take place in the resistant cost population.
dc.formatpdf
dc.formatapplication/pdf
dc.languageeng
dc.publisherBulletin of Entomological Research
dc.relationv. 98, Issue 4, p. 417-424, August 2008
dc.rightsCambridge University Press
dc.subjectInsecticide resistance
dc.subjectAmylase
dc.subjectLipase
dc.subjectTrehalase
dc.subjectFitness cost
dc.subjectCost mitigation
dc.titleEnhanced activity of carbohydrate- and lipid-metabolizing enzymes in insecticide-resistant populations of the maize weevil, Sitophilus zeamais
dc.typeArtigo


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