The effect of piperonyl butoxide on the specific activity of glutathione s-transferase of the common pistachio psyllid, Agonoscena pistaciae

Glutathion S-transferase enzymes have an important role in the detoxification of pesticides compounds and the resistance of insects to insecticides. In this study, the activity of glutathione S-transferase enzyme between summer and winter forms of pistachio psyllid, were measured and the effect of different concentrations of PBO (0.5, 1,2,4 and 8 mg/Lit) on the inhibition of activity of this enzyme were investigated by using of 1- chloro- 2,4- dinitrobenzene (CDNB) as a substrate. In addition, the activity of glutathione S-transferase were determined at 0, 1, 2, 4 and 6 hour after treatment the adults by the concentration of PBO that had maximum inhibition on this enzyme. The results indicated that there is no significant deference between the activity of enzyme in different forms of pistachio psyllid (P<0.05) and the lowest activity of glutathione S-transferase or highest inhibition were obtained in 0.5 mg L-1 of PBO and the maximum inhibition were done at 4 hour after the synergism application. According to these results, it seems that by using the suitable dose of PBO and matching the time that the synergist has maximum inhibition to the glutathione S-transferase we will be able to promote the resistance management of pistachio psyllid to pesticides.