Peroxidase activity and isoenzymes profiles in maize dwarf mosaic potyvirus leaves

Abstract

Infection of maize plants with two different viruses: maize dwarf mosaic potyvirus (MDMV) or sugarcane mosaic potyvirus-strain Yu (SCMV-YU), which produced the same type of symptom, resulted in identical changes in peroxidase activity and changes in the profiles of peroxidase isoenzymes. The peroxidase activity kept changing during infection. An increase in the activity of peroxidase was evident at the early stages of the infection. Very low activity of this enzyme was recorded on the 9th day after inoculation when clear symptoms of virus infection were expressed. The level of peroxidase activity was also dependent on the age of the infected leaves. The change in peroxidase activity was negligible in mature leaves and very pronounced in young fast growing leaves.The isoenzyme profiles of peroxidase investigated in this study, suggested that infection with MDMV or SCMV-YU involved in the senescence reaction was produced by the virus infection.

Infekcija biljaka kukuruza virusima mozaične kržljavosti kukuruza ili mozaika šećerne trske-soj Yu, koji prouzrokuju isti tip simptoma, izaziva identične promené u aktivnosti i profilima izoenzima peroksidaze. Aktivnost peroksidaze se menja u toku infekcije sa povećanjem na početku infekcije. Veoma niska aktivnost ovog enzima zabeležena je devetog dana po inokulaciji u vreme kada su ispoljeni jasni simptomi virusne infekcije. Nivo aktivnosti peroksidaze zavisi i od starosti lišća. Promene aktivnosti peroksidaze u listovima završenog rasta su beznačajne, a veoma izražene u listovima intenzivnog rasta. Utvrđeno je postojanje 19 izoenzima različite molekulske mase, čija jačina ispoljavanja u različitim danima po inokulaciji upućuje na to da infekcije ispitivanim virusima izazivaju reakcije karakteristične za starenje biljke.