关键词: 棉铃虫, 植物次生物质, 单宁酸, 谷胱甘肽S转移酶, 诱导

Abstract: The effects of tannic acid on the specific activity of glutathione S-transferases (GSTs) in the cotton bollworm, Helicoverpa armigera(Hübner) fed on artificial diet with tannic acid were investigated. The results showed that the specific activity of GSTs was lowest in the egg stage and highest in the 5th－6th instars of the cotton bollworm. When cotton bollworms were treated with 0.005% tannic acid, the specific activity of GSTs in the 5th and 6th instars was greatly reduced (59% and 67% of the control respectively), while it was induced in the 3rd instar and not different from the control in other developmental stages. The effects of tannic acid on GSTs specific activity were dependent on dosage and time. Low dosage and/or short time of treatment with tannic acid induced high level of GSTs specific activity in both midgut and fat body, while high dosage and/or long time of treatment either depressed GSTs activity or had no effect on it. When cotton bollworms were fed on artificial diet with tannic acid over 4 continuous generations, their GSTs specific activity in the 6th instar was all depressed in midgut, while either depressed or not different from control in fat body. After 4 generations treatment with tannic acid, the larvae of cotton bollworms were more susceptible to deltamethrin, but had no significant difference in susceptibility to parathionmethyl.

Key words: Helicoverpa armigera, allelochemicals, tannic aci d, glutathione Stransferases, induction