Browsing by Author "Iscan, Mesude"

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Analysis of Molecular Resistance Mechanisms in Helicoverpa Armigera (Hubner) (Noctuidae: Lepidoptera) Populations Under Pyrethroid Stress in Turkey
(Gazi Entomological Research Soc, 2014) Konus, Metin; Karaagac, Sakine Ugurlu; Iscan, Mesude
Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is a major pest of economically important crops such as cotton, tomato and soybean. In order to control this pest, pyrethroid insecticides have been extensively used in farming areas all over the world. However, applications of excessive amounts of these insecticides can result in resistance development in the field populations of H. armigera. Resistance to the pyrethroids, beta-cypermethrin and lambda cyhalothrin, was analysed using bioassays. It was found that a canakkale field population of H. armigera field showed low (2.1-fold) and moderate (14.5-fold) resistance levels for beta-cypermethrin and lambda-cyhalothrin, respectively. Furthermore, expressions of selected CYP450, GST and esterase genes of H. armigera canakkale field populations were compared to those of a susceptible strain using real-time PCR. Our results indicate that H. armigera reacts to pyrethroids mainly by increasing expression levels of CYP450s such as CYP9Al2 and CYP9A14. However, GST and esterase genes expression levels were not significantly altered in a field population. GSTs and esterases were also analyzed using biochemical assays. While GSTs and esterase genes were not found to be up-regulated in the real-time PCR, except GST-DCNB activity, the biochemical assays also showed no significant increases in enzyme activities in the canakkale field population as compared to the susceptible strain. Consequently, CYP9Al2 and CYP9A14 together with certain GSTs, catalyzing DCNB substrate, are proposed to be involved in the metabolic responses against beta-cypermethrin and lambda-cyhalothrin insecticides in field population of H. armigera from Turkey.
A Combined Method of Protein Extraction From Unorthodox Plant Samples for Proteomics
(Bentham Science Publ Ltd, 2021) Yilmaz, Can; Iscan, Mesude
Aim: This study aimed to generate an improved method of protein extraction and purifi-cation from plant tissues containing very high amounts of phenolic compounds and other interfer-ing biomolecules. Background: Protein extraction at proteomic studies on some plant species, including conifers, is challenging, and the yield and quality are unpredictable. Objective: Two popular protocols were combined with each other to construct a novel one with en-hanced abilities to produce higher purity of samples compatible for high precision molecular sys-tems and analysis. Methods: The new method was compared with the other two for their efficiencies in classical SD-S-PAGE, 2-DE and capillary chromatography applications. Results: All three methods were comparable in SDS-PAGE procedure; however, only the new method created acceptable gel images in 2-DE. Bioanalyzer results, also, demonstrated that the new method provided protein samples pure enough to be used in capillary chromatography with 2 times more peaks in electropherograms with lower noise and higher total relative protein concentra-tions closest to the applied amount. Conclusion: The new combined method is a successful alternative for plant proteomicists with higher yield and quality of proteins from recalcitrant tissues. Other: The new method could be preferred, especially, for high-tech, sensitive proteomic analysis.
Effects of Rheum Ribes Ethanolic Extracts on Cytochromes P450 1b1 (Cyp1b1) Gene Expression and Glutathione-S (Gst) Activity in Hl-60 Cells
(Taylor & Francis inc, 2008) Uyar, Pembegul; Ozgokce, Fevzi; Coruh, Nusen; Iscan, Mesude
Molecular Adaptations of Helicoverpa Armigera Midgut Tissue Under Pyrethroid Insecticide Stress Characterized by Differential Proteome Analysis and Enzyme Activity Assays
(Elsevier Science inc, 2013) Konus, Metin; Koy, Cornelia; Mikkat, Stefan; Kreutzer, Michael; Zimmermann, Ralf; Iscan, Mesude; Glocker, Michael O.
Helicoverpa armigera is an insect that causes important economic losses in crops. To reduce this loss, pyrethroids have been commonly used against H. armigera in farming areas. However, excess and continuous usage of pyrethroids cause resistance in H. armigera. Therefore, expressions of midgut proteins of two H. armigera field populations were compared to those of a susceptible strain by 2-D PAGE and MALDI-ToF-MS. Our results indicate that H. armigera reacts to pyrethroid-induced stress mainly by increasing the expression of energy metabolism-related proteins, such as ATP synthase and arginine kinase. NADPH cytochrome P450 reductase, also up-regulated, could play a role in detoxification of toxic pyrethroid metabolites, such as 3-phenoxybenzaldehyde. Interestingly, while GSTs were not found up-regulated in the comparative proteome analysis, biochemical assays showed significant increases of enzyme activities in both field populations as compared to the susceptible strain. Similarly, although esterases were not found differentially expressed, biochemical assays showed significant increases of esterase activities in both field populations. Thus, esterases are also proposed to be involved in metabolic responses towards pyrethroid insecticide-induced stress. In conclusion, we suggest increased energy metabolism in the midgut tissue of H. armigera as a general prerequisite for compensating the costs of energy-consuming detoxification processes. (C) 2013 Elsevier Inc. All rights reserved.
Real-Time Pcr Analysis of Pyrethroid Resistance in Helicoverpa Armigera From Turkey
(Turkish Biochem Soc, 2014) Konus, Metin; Karaagac, Sakine Ugurlu; Iscan, Mesude
Aim: Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) is a polyphagous pest of a wide range of crops such as cotton, tomato and soybean. Pyrethroid insecticides have commonly used against it in agricultural areas, but excess amount applications of them result in resistance development in the field populations of H. armigera. Resistance development usually occurs with increased metabolism of certain enzymatic systems such as CYP450, GST and esterases. Therefore, expressions of selected CYP450, GST and esterase genes of H. armigera field populations (Adana and Mardin) were compared to those of a susceptible strain by real-time PCR method for analyzing role of these systems in pyrethroid resistance development of H. armigera. Material and Methods: Real-Time PCR Method Results: It was found that H. armigera reacts to pyrethroids mainly by increasing expressions of CYP9A14 gene together with CYP4S1 and CYP9A12 genes. However, analyzed GST and esterase genes expression were not significantly changed in field populations. Conclusion: Consequently, while CYP450 enzyme system is actively involved in pyrethroid resistance, GSTs and esterases enzyme systems don't seem to be actively involved in resistance development against pyrethroid insecticides in H. armigera field populations from Turkey.