Host plant effects on the presence of superoxide dismutase isoforms in gypsy moth midgut

Abstract

The presence of copper-zinc containing superoxide dismutase (Cu-Zn SOD) isozymes was investigated in the midgut tissue of gypsy moth (Lymantria dispar) caterpillars (4(th), 5(th) and 6(th) instar) reared on favourable (oak tree leaves) and unfavourable host plants (locust tree leaves) and originating from different populations (oak and locust tree forest). One isoform was found in the midguts of 4th instar caterpillars fed with oak leaves while two isozymes were present in the midgut of locust fed caterpillars regardless of the population origin. Two isozymes were also characteristic for 5(th) instar caterpillars within both populations regardless of long-term or short-term (3 days) host plant effects. In the 6(th) instar, two Cu-Zn SOD isozymes were found in the gypsy moth midguts, with the exception of the group fed with locust leaves and originating from locust tree forest, where only one isozyme was observed. The black locust diet provoked an increase in midgut protein content in the 6(th) instar gypsy moth originating from the locust forest population but not in those from the oak forest.