Department of Biochemistry, Agricultural and Pedagogic University, Siedlce, Poland.
Herbivores developed defensive mechanisms towards various plant xenobiotics. The most important one involves detoxication enzymes system. Hitherto studies showed that I phase detoxifying enzymes (polysubstrate monooxygenases) are not present at high activity in the cereal aphid tissues. For this group of insects that are phloem sap feeders, II phase detoxifying enzymes (transferases) showed primary importance in detoxication of plant xenobiotics. So far, activity of glutathione S-transferase and UDP-glucosyl transferase was found in the cereal aphid. In the present paper we report on activity of sulfotransferases and phosphotransferases in bird cherry-oat aphid.Presence of the activity of the sulfotransferases and phosphotransferases within grain aphid tissues has been proved. Among studied morphs, the highest activity of the sulfotransferases showed winged migrants, instead larvae had the highest activity of the phosphotransferases. When the aphids fed on less suitable winter wheat and triticale cultivars (rich in xenobiotics), a slight induction in activity of the sulfotransferases was found, in comparison to aphids fed on susceptible cultivars (poor in xenobiotics). However, for the phosphotransferases the opposite trend was observed. The possible function of the studied transferases in the bird cherry-oat aphid biochemical adaptation to cereal xenobiotics is discussed.