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(204) Differences in detoxifying enzyme patterns of epigeic predatory, detritivore and herbivorous beetles from metal polluted areas. Bednarska, Katarzyna1, Augustyniak, Maria1, Kafel, Alina 1, Migula, Pawel1, Woloszyn, Mariusz1, 1 ABSTRACT- This is a part of a larger project focused on effects of chronic pressure of metals at sublethal concentrations. The aim was to answer whether trophic groups of invertebrates possess similar adaptive mechanisms at different biological organisation levels to cope with the environmental stress. Detoxification enzyme responses were analysed in beetles representing different trophic groups: detritivores - Geotrupes geotrupes, Silpha carinata, Necrophorus vespillo, predatory - Staphylinus caesareus, Pterostichus oblongopunctatus, P. versicolor; and fitophagous - Phyllobius cervinus. All beetles were collected at five grassland and five forest sites along metal polluted gradients in southern Poland (from 10,000 to 150 mg Zn kg-1 of humus). Activity profiles of glutathione S-transferase (GST), catalase (CAT) and glutathione peroxidase (GPOX) were assessed in insects collected throughout the season. CAT, serving as a major defence against oxygen radical toxicity was the highest in a dung beetle, without significant differences between the sites. CAT activity in other detritivores was about 10 times lower, parallel to the metal load. Fitophagous Phyllobius had a similar activity pattern, but never reached the highest level found in the dung beetles. Both predatory carabids showed an opposite profile, with a negative correlation between activity and the metal load. A second phase of enzymatic detoxification appeared less important in the dung beetles. Their GST activity was negatively correlated with the levels of metals. A similar pattern characterised also P. cervinus and silphid beetles. Carnivorous carabids had a bell-shaped pattern of the GST activity. Conjugation processes with the use of glutathione were more effective in moderately polluted areas. Inhibition of the GST suggests that at highly polluted areas their tolerance limits were exceeded. Key words: trophic groups , enzymes, beetles, detoxication |
