THE INFLUENCE OF TAPHRINA DEFORMANS (BERKELEY) TULASNE (PEACH LEAF CURL) ATTACK ON THE ACTIVITY OF SOME OXIDOREDUCTASES IN CULTIVAR CARDINAL

Abstract

Taphrina deformans (Berk.) Tul. is the causal agent of peach leaf curl, a fungal disease which in present is widespreaded in all places where peaches and other related species are cultivated. In this paper are presented the result concerning the influence of the attack of fungus Taphrina deformans on the activity of catalase (EC 1.11.1.6), peroxidase (EC 1.11.1.7) and polyphenoloxidase (EC 1.10.3.1) compared with the activity of this oxidative enzymes in healthy leaves at cultivar Cardinal. The determination of enzymes activity were carried out at 4.05.2009, 18.05.2009, 25.05.2009, 1.06.2009 and 8.06.2009. Catalase activity was higher in diseased leaves at the beginning of the infection and decreased with the evolution of disease simptoms. Peroxidase and polyphenoloxidase activities were found higher in diseased leaves when compared with enzymes activity from healthy leaves, at all dates of the determination. Polyphenoloxidase dicreased with leaves age, but remained considerably grater in infected tissues. This study suggest that the accumulation of reactive oxygen species in peach tissues, as a response at fungus attack, increased activities of catalase, peroxidase and polyphenoloxidase, this enzymes beeing involved in host defence mechanisms.