© 1996 Heron Publishing—Victoria, Canada
Characterization of glutathione S-transferases in needles of Norway spruce trees from a forest decline stand
Peter Schröder (1, 2) and Andreas E. Wolf (1)
1. Fraunhofer Institut für Atmosphärische Umweltforschung, Garmisch-Partenkirchen, Germany / 2. Institut für Biochemische Pflanzenpathologie, GSF-Forschungszentrum für Umwelt und Gesundheit, D-85758 Oberschleißheim, Germany / Received April 18, 1995
Summary
Glutathione S-transferases (GST) detoxify many electrophilic xenobiotics, including several volatile organic compounds and pesticides.
The GST activity for the conjugation of several xenobiotic substances was isolated from needles of Norway spruce (Picea abies L. Karst.) trees from a forest decline stand in the northern alps. Trees that exhibited different degrees of damage were
selected from several stands in an altitude profile. The GST activity toward 1-chloro-2,4-dinitrobenzene (CDNB) in crude protein
extracts of needles showed a seasonal pattern with highest activity during summer. The GST activity exhibited a strong dependence
on the altitude of the stand showing highest activities in trees growing in the valley and lowest activities in trees growing
in the summit regions of the mountain. When cytosolic GST from needles of healthy and damaged trees was purified, trees of
healthy appearance exhibited three distinct GST isozymes with activities for the conjugation of CDNB and 1,2-dichloro-4-nitrobenzene
(DCNB), whereas severely defoliated trees exhibited four GSTs with additional activity for the conjugation of ethacrynic acid.
The main GST isozymes catalyzing the conjugation of CDNB differed in molecular weight, isoelectric point and catalytic properties
between damaged and healthy trees.
Keywords:
detoxification, isozymes, Picea abies, xenobiotics.
