ACTIVITY OF PEROXIDASES IN PLANT MATERIAL INFECTED WITH ERWINIA AMYLOVORA
Based on preliminary results on antioxidant enzymes the present investigations were focused on the changes in peroxidase activities during the infection process and disease development. Assays were performed with apple seedlings and cultivars grown under greenhouse conditions as well as with in vitro plantlets (Golden Delicious, Pinova, Greensleeves, M26). The influence of pesticides, e.g. Prohexadione-Ca, on the level of peroxidases was checked in context to the control of the disease. Total peroxidases were determined by spectrophotometric measurements. Iso-enzymes and H2O2 formation were visualized by discontinuous non-denaturating electrophoresis. Independent of the plant system an increase of peroxidase activities was observed during disease development. However, no direct link to the susceptibility of cultivars or to the influence of chemicals was observed. Responses of Malus tissue (leaf, stem) to Erwinia amylovora infections was documented by fluorescence microscopy. The results give an overview on the localization of peroxidase activities and the production of cellular substances (e.g. flavanoids, lignin) involved in defense mechanisms. The effect of bacterial strains, differing in pathogenicity, is shown by cellular peroxidase production.
Keck, M., Richter, S., Suarez, B., Kopper, E. and Jungwirth, E. (2002). ACTIVITY OF PEROXIDASES IN PLANT MATERIAL INFECTED WITH ERWINIA AMYLOVORA. Acta Hortic. 590, 343-350
fire blight, plant material, chemical control, peroxidases