© 1993 Heron Publishing—Victoria, Canada
Seasonal changes in the axial distribution of peroxidase activity in the xylem sap of beech (Fagus sylvatica L.) trees
Andrea Polle (1, 2, 3) and Vjekoslav Glavac (4)
1. Fraunhofer Institut für Atmosphärische Umweltforschung, Kreuzeckbahnstrasse 19, D-82467 Garmisch-Partenkirchen, Germany / 2. Albert-Ludwigs-Universität Freiburg, Institut für Forstbotanik und Baumphysiologie, Flughafen 17, D-79085 Freiburg, Germany / 3. Author to whom correspondence should be addressed / 4. Fachbereich Biologie/Chemie der Gesamthochschule Kassel, Heinrich-Platt-Strasse 40, D-34132 Kassel, Germany / Received May 10, 1993
Summary
Xylem sap was collected from trunk segments of adult beech (Fagus sylvatica L.) trees by water displacement. Peroxidase activity was analyzed in xylem saps collected in different phases of the yearly
growth cycle and from different heights up the trunks (up to 14 m). The xylem saps contained two major peroxidase isozymes
with acidic isoelectric points of 4.1 and 4.6, respectively. Mean peroxidase activity was low during the emergence of the
new leaves and high in summer and in winter. In the cold season, peroxidase activity decreased from the stem base to the top,
whereas significant gradients were not observed during the vegetative period.
Keywords:
annual growth cycle, isozymes, trunk height, xylem sap.
