Prothoracicotropic hormone-producing neurosecretory neurons and antioxidative defense in midgut of Lymantria dispar in trophic stress

Authors : Vesna PERICMATARUGA, Milena VLAHOVIC, Marija MRDAKOVIC

Pages : 403-411

Doi:10.3906/biy-1309-57

View : 20 | Download : 6

Publication Date : 2014-12-01

Article Type : Research Paper

Abstract :As a very invasive insect species, Lymantria dispar is adaptable and sensitive to a changing environment. In insects the neuroendocrine system first reacts to stress by production of prothoracicotropic neurohormones insert ignore into journalissuearticles values(PTTH); that control ecdysteroid synthesis insert ignore into journalissuearticles values(morphogenetic and stress hormones);. In this article, we report changes in the L2` brain neurosecretory neurons that synthesize PTTH in L. dispar larvae after feeding on locust tree leaves insert ignore into journalissuearticles values(Robinia pseudoacacia);, an unsuitable host plant. Groups of larvae insert ignore into journalissuearticles values(n = 20 per experimental group); were offered this in comparison with oak leaves insert ignore into journalissuearticles values(Quercus robur);, a suitable control diet, for 3 days after molting into the fourth instar. L2` neurons and their nuclei were enlarged and the amount of neurosecretory product in the cytoplasm was increased insert ignore into journalissuearticles values(15.5%); after consumption of locust tree leaves in comparison to the control. Furthermore, activities of the following antioxidative defense components were estimated: superoxide dismutase insert ignore into journalissuearticles values(SOD);, catalase insert ignore into journalissuearticles values(CAT);, and amount of glutathione in the midgut. Higher SOD activity insert ignore into journalissuearticles values(13.85 ± 0.9 U/mg prot.); and glutathione amount insert ignore into journalissuearticles values(0.56 ± 0.06 mMGSH/g tissue); but unchanged CAT activity was found in the midgut of larvae offered locust tree leaves when compared to the control.
Keywords : Key words Oak leaves, locust tree leaves, survival, superoxide dismutase, catalase, glutathione