Determination of esterase enzyme polymorphism in house fly (Musca domestica L.) populations in Turkey

The objective of this study was to determine esterase enzyme polymorphism in 16 natural Musca domestica L. populations from the Aegean and Mediterranean regions of Turkey by using the native polyacrylamide gel electrophoresis (PAGE) technique. The high level of genetic variation among populations and species make esterase enzymes an important tool for analyzing genetic differentiation and evolutionary relationships in insects. In the present study, 22 a-esterase bands were detected by using a-naphthylacetate as a substrate. The frequencies of these bands were variable within and among populations. Neither regional nor population specific esterase bands were detected. The origin of speciation of M. domestica is unknown, but the southern Palearctic region, particularly the Middle East, has been suggested as the likely candidate location. Studies on genetic diversity in M. domestica are important for providing knowledge that will better enable us to understand the origin of this species. This preliminary study is important because it is the first in the literature to illustrate the esterase isozymes and their frequencies for this part of the world. For a better evaluation and understanding of the ongoing situation of M. domestica populations in Turkey as a Palearctic country, however, further research is needed to screen not only populations from these 2 regions but also from other regions for many other enzyme and DNA loci

POTENTIAL BIOMONITORING USE OF VARIATIONS IN ESTERASE, GLUTATHIONE S-TRANSFERASE, AND ACETYLCHOLINESTERASE ACTIVITIES IN Musca domestica L.

Many ecosystems have been under the continuous influx of both organic and inorganic xenobiotics, including organophosphorus compounds, as a result of intense agricultural and industrial activities. Biochemical biomarkers have been increasingly used in determining the effects of xenobiotics in studies aimed at assessing ecological risks on ecosystems. In this study, as a model organism, housefly (Musca domestica L.) samples collected from 48 different locations belonging to 16 provinces in Aegean and Mediterranean regions of Turkey were screened for their variation in glutathione S-transferase (GST), percent remaining acetylcholinesterase (AChE) and general esterase activities, as biomarkers of environmental pollution. In all Aegean populations, the percent remaining AChE activities were found much higher than that of the control WHO strain indicating heavy organophosphate usage in this region, and a resistance mechanism likely developed as AChE insensitivity. However, the results also showed that compared with Aegean region, the populations from Mediterranean Region are more sensitive to this group of insecticides on the base of this enzyme. GST activities were also much higher than that of the susceptible control in all, except Osmaniye, populations that is indicative of intense usage of xenobiotics in these regions. General esterase activity assays resulted in the preference of alpha-NA in higher proportions than beta-NA as substrate. Also the results of these assays can be interpreted as development of resistance on the basis of mutant ali-esterase hypothesis to organophosphate group of insecticides in some areas screened. The concurrence of the significant variations observed in housefly AChE, GST, and general esterase enzyme activities, with the different xenobiotic stress conditions of locations emphasize their suitability to be utilized as biomarkers in biomonitoring

Effect of fire-derived chemicals on germination and seedling growth in Mediterranean plant species

The promoting effect of smoke-derived chemicals (e.g. karrikinolide and cyanohydrin) on germination in many plants from Mediterranean-type ecosystems such as South Africa and south-western Australia is well documented. However, very little is known about (1) the relative importance of different compounds and their possible interactive effects, (2) their role in enhancing seedling growth in wild plants, and (3) their effect on the germination of plants in the Mediterranean Basin. To fill these gaps in knowledge, we performed experiments to evaluate the effect of smoke water, karrikinolide, mandelonitrile (a cyanohydrin analogue), potassium nitrate and gibberellic acid on the germination and seedling growth of 37 species from the Mediterranean Basin. The results suggest that germination and/or seedling growth of 21 species are enhanced by at least one of the fire-derived chemicals. There were positive correlations between most of the compounds tested in terms of germination response, but synergetic and inhibitory effects were also detected. Stimulation of germination was most prominent in species with annual life cycles. Fire-derived chemicals were more effective in stimulating root growth than shoot growth. In conclusion, we provide novel evidence that the recruitment of different Mediterranean species may be enhanced by different smoke compounds, and that synergetic and inhibitory effects of chemical compounds are important in the germination ecology of plants.This study was financially supported by the Scientific Research Projects Coordination Unit of Muğla Sıtkı Koçman University (grant number 15/153)Peer reviewe

Antioxidative Defence Mechanisms in Tomato (Lycopersicum esculentum L.) Plants Sprayed with Different Pesticides and Boron compounds

Oxidative stress was investigated in Lycopersicum esculentum L. by applying various pesticides and boron compounds for two years, near Ortaca-Muğla. The field sections were treated separately by commercial pesticides and boron compounds i.e. tarimbor (TB), boric acid (BA), laser (LA), zoom (ZO) and admiral (AD). During first year, boric acid (BA-1) caused highest increase in total chlorophyll (TCh) content (158.41 μg g-1) while the second dose (BA-2) decreased it (103.11 μg g-1). During second year, higher doses of tarimbor (236.49 μg g-1) caused increase in total chlorophyll (TCh) while ZO treatment decreased it (142.55 μg g-1) (control: 149.55 μg g-1). TB-1 caused the highest increase in proline content (33.52 nmol g-1) while highest reduction was observed in boric acid (BA-2) (22.51 nmol g-1) as compared to control group (26.77 nmol g-1). During the first year, an increase of boric acid and tarimbor concentrations decreased malonaldehyde (MDA) while during the second year, both increases and decreases were observed in the MDA amount. Highest superoxide dismutase (SOD) amount was found in the first year ZO treated plants i.e. 70.35 unit SOD/mg protein while TB-1 treatment caused the highest decrease in the SOD amount i.e. 35.21 unit SOD/mg protein (control: 45.23 unit SOD/mg protein)