Investigation on the effect of imidacloprid concentrations on lipid peroxidation and antioxidant defense enzyme activity in the termite Microcerotermes diversus (Isoptera: Termitidae)
Paper ID : 1304-3IICE (R1)
Authors:
mina darmiani *1, Behzad Habibpour1, Payman Hassibi2
1Department of Plant Protection, College of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
2Department of Agronomy and Plant Breeding, College of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract:
Microcerotermes diversus Silvestri is one of the most important pests of wooden and cellulosic products in residential areas, as well as in agricultural lands and green spaces in different parts of Iran, including Khouzestan province. Chemical control is practiced against the pest using various pesticides including imidacloprid. It is a contact/ingestion pesticide that causes the death of an insect through disruption of postsynaptic neuronal acetylcholine receptors. The aim of this study was to determine a biomarker by measuring the activity of antioxidant enzymes and the amount of lipid peroxidation in inducing oxidative stress in association with imidacloprid exposure. For this purpose, worker casts were collected using beech wood. Then, they were exposed to concentrations of 5, 10, 25 and 50 ppm of imidacloprid sprayed on cellulosic substrate. Afterwards, they were transferred onto filter paper. Indices such as malondialdehyde (MDA) and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and glutathione reductase (GR) were studied in the worker cast. Then we measured the effect of treatments on oxidative stress biomarkers such as MDA, as a product of lipid peroxidation, and activity of antioxidant enzymes such as SOD, CAT, POX, and GR of worker cast. A completely random design was used with four replications. Laboratory trials were performed in a dark incubator at 28±2℃ and 85±5%RH, respectively. Data were analyzed by one way- ANOVA to determine significant differences between means. The units of measurement of enzyme activity was U/mg of protein. Results showed that the content of MDA and the activity of SOD and CAT enzymes in the termite hemolymph increased under the treatment of insecticide compared to those in control, but the activity of POX and GR enzymes decreased. Based on the results, these parameters could be used as biomarkers to determine the level of oxidative stress in the body of termites.
Keywords:
Malondialdehyde, Superoxide dismutase, Catalase, Peroxidase, Glutathione reductase.
Status : Paper Accepted (Poster Presentation)