关键词: 储藏物害虫, 咖啡豆象, 气调, 气调抗性, 解毒酶, 酶活性, 酶动力学

Abstract: To clarify the effect of controlled atmosphere (CA) on stored pests and enzyme activities related to the development of resistance, the effect of CA with enriched CO₂ (75% CO₂, 5% O₂ and 20% N₂ ) on the activities of carboxylesterase (CarE), acid phosphatase (ACP) and glutathione S-transferases (GSTs) from an experimental population of Araecerus fasciculatus (De Geer) were investigated. The results showed that CarE activities were significantly affected by CA with exposure time, increased by 35.41%, 55.02% and 88.98% at 3 h, 6 h and 9 h, respectively, after exposure compared with the control. The CA treatment increased the Michaelis-Menten (M-M) kinetic constant, _Vmax, of CarE by 26.13%, 31.77% and 57.12%, respectively at 3 h, 6 h and 9 h after exposure, but had no effect on the M-M constant, K_m. CA treatments of 3 h, 6 h and 9 h increased the specific activity of ACP by 34.53%, 72.45% and 126.37%, respectively. Compared to the control, the specific activities of GSTs in adults exposed to CA for 3 h, 6 h and 9 h were increased by just 5.40%, 8.40% and 17.59%, respectively. These results suggest that A. fasciculatus can adjust the activity of some detoxification enzymes and the kinetics of CarE-catalyzed reactions under the stress of CA. Under CA conditions, the catalytic activity of some detoxification enzymes towards their substrates were enhanced, potentially providing the ability for the pest to adjust its metabolic activity against extreme conditions. This study provides insights into insect responses to CA treatment and the mechanism of CA resistance or tolerance.

Key words: Stored product pest, Araecerus fasciculatus, controlled atmosphere (CA), resistance to controlled atmosphere, detoxification enzyme, enzyme activity, enzyme kinetics