Activity of arginase within winter triticale seedlings attacked by grain aphid [Sitobion avenae F.]

Arginase (EC 3.5.3.1) catalyses biodegradation of L-arginine to L‑ornithine and urea. The aim of the study was to determine changes in arginase activity within seedlings of winter triticale caused by Sitobion avenae feeding. Obtained results showed an increase in the arginase activity within shoots of winter triticale seedlings susceptible Tornado cv and decrease in less susceptible Witon cv after 24 h of the grain aphid feeding. Further aphid feeding caused decrease in activity of the enzyme within shoots of the both studied cultivars and final induction after two weeks of feeding. In the roots of Tornado cv the enzyme activity decreased during the first week of the aphid feeding and slightly increased after two weeks. However, in analogous parts of the Witon cv seedlings settled by S. avenae an increase in arginase activity was observed after 24 h and decrease after one week was noticed. Importance of the arginase in interactions between the winter triticale and S. avenae is discussed