Lysozyme response to wounding and bacterial inoculation in larvae of Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

“Lysozyme response to wounding and bacterial inoculation in larvae of Spodoptera frugiperda (Lepidoptera: Noctuidae)”. Lysozyme is an antibacterial agent and one of the main components of insects ? humoral immune response. The effect of tegumentary injury and bacterial inoculation on the expression and activity of lysozyme in Spodoptera fru- giperda hemolymph was determined. Three groups of larvae were studied. A punction injury was performed on the first group (1). The same was done to a second group adding inocu- lation with Micrococcus luteus (2). A third group was neither injured nor inoculated (3). Lysozyme activity and a protein profile were determined in hemolymph. No significant differ- ences were found in lysozyme activity between groups 1 and 3. However, in group 2 activity was significantly greater, three times more compared to the other groups. Electrophoresis showed a greater number of protein bands for groups 1 and 2 compared to group 3, but in group 2 the intensity of these bands was lower than in group 1, except for the lysozyme band. The occurrence of new protein synthesis involved in the defense system or an in- creased synthesis thereof, including lysozyme, would appear when injury plus inoculation oc- curred.