Acta Entomologica Sinica (2007) 50, 1225-1231
Fang Tang, Zhu. Tao, Xi-Wu Gao and Ao-Jin Yan (2007)
[Inhibition of glutathion S-transferases activity from Odontotermes formosanus (Shiraki) and Reticulitermes chinensis Snyder by seven inhibitors]
Acta Entomologica Sinica 50 (12), 1225-1231
Abstract: The optimum reaction condition of glutathion S-transferases (GSTs) in termites was studied using the biochemistry methods. Furthermore, the inhibition of GSTs from Odontotermes formosanus (Shiraki) and Reticulitermes chinensis Snyder by seven inhibitors (quercetin, tannic acid, abamectin, fenpropathrin, acetamiprid, phoxim, beta-cypermethrin), were determined. The results indicated that the optimum pH value was 6.5, the optimum reaction time was 2 min, and the optimum temperature was 25°C for GSTs in termites. The Michaelis constant (KmCDNB and KmGSH) of GSTs hydrolyzing CDNB and GSH were 0.11±0.02 mmol/L and 0.81±0.16 mmol/L in O. formosanus, respectively, not significantly different from that of GSTs in R. chinensis (0.12±0.03 mmol/L and 1.03±0.31 mmol/L). The maximum velocities (VmaxCDNB and VmaxGSH) hydrolyzing CDNB and GSH were 425.92±19.67 nmol/(min·mg) and 534.86±39.05 nmol/(min·mg) for O. formosanus, and 544.39±37.19 nmol/(min·mg) and 715.45±83.68 nmol/(min·mg) for R. chinensis, respectively. When the final concentration of plant allelochemicals and insecticides was 2×10-5 mol/L, inhibition to GSTs from R. chinensis by quercetin and phoxim was stronger than to that from O. formosanus. The percentage of inhibition of GSTs activity from R. chinensis was 62.28% and 44.89% and the percentage of inhibition of GSTs from O. formosanus was 54.96% and 28.36% by the above plant allelochemicals and insecticides, respectively, when the concentration of inhibitors was 2×10-5 mol/L. When the final concentration of plant allelochemicals and insecticides was 2×10-5 mol/L, inhibition to GSTs from O. formosanus by beta-cypermethrin, fenpropathrin, acetamiprid and tannic acid was stronger than to that from R. chinensis. The percentage of inhibition of GSTs activity from O. formosanus was 39.43%, 72.07%, 52.24% and 82.19%, and the percentage of inhibition of GSTs from R. chinensis was 14.96%, 40.23%, 39.96% and 57.80 by the above plant allelochemicals and insecticides, respectively, when the concentration of inhibitors was 2×10-5 mol/L. There was no difference in the percentage of inhibition of the activity of GSTs from O. formosanus and R. chinensis when the concentration of abamectin was 2×10-5 mol/L. The results suggested that the difference in GST sensitivity to insecticides existed between the two termites. Furthermore, the inhibition of GST activity by plant allelochemicals and insecticide was increased with the increasing of insecticide concentration from 3.2×10-8 to 2×10-5 mol/L.
(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:
molecular biology - genes
pesticide resistance of pest
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Reticulitermes chinensis | ||||
| Odontotermes formosanus |
