Arda Acemi

Analysis of plant growth and biochemical parameters in Amsonia orientalis after in vitro salt stress

This study aimed to better understand the limited natural distribution of the endangered ornamental plant Amsonia orientalis Decne. by focusing on salt stress, a common limiting factor of plant growth. Plants were subjected to in vitro salt stress at concentrations between 25 and 150 mM. In general, shoot and root lengths, root number, and total protein, chlorophyll a and carotenoid content were negatively influenced at NaCl concentrations above 25 mM. Hydrogen peroxide, malondialdehyde and proline content all gradually increased with increasing salt concentration. Activity levels of the antioxidant enzymes catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) were all at their maximum in plants cultured in medium containing 50 mM NaCl. Compared to control cultures, an overall upward trend in POD activity was observed with increasing salt concentration, while the activity levels of SOD and CAT increased at lower concentrations but were limited at elevated concentrations of NaCl. These results suggest that A. orientalis prefers soils with no or very low salt but can tolerate NaCl up to a concentration of 50 mM.

Genetic diversity of Amsonia orientalis

Amsonia orientalis Decne. (Apocynaceae), is a rare and threatened plant species which is located only in a constricted area in northeast of Greece and northwest of Turkey in the world. Although phylogenetic analysis depending on nucleotide sequences of genes from different sources (nucleus, mitochondria and chloroplast) became a major tool for classification of plant species, there is still a big lack of information about A. orientalis in the international molecular data bases such as NCBI. In the current study, we phylogenetically analyzed three commonly used molecular markers (18S rDNA, 18S-28S rDNA-ITS region and trnL-F intergenic spacer) from A. orientalis samples collected from Turkey to determine the genetic diversity and also to question the systematic position of A. orientalis. As a result, A. orientalis samples clearly showed close relation with Alyxieae tribe rather than Vinceae. And this result brings the necessity to reconsider the morphological characters that have used to delimit the tribes of Rauvolfioideae.

Purification of peroxidase from Amsonia orientalis by three-phase partitioning and its biochemical characterization

ABSTRACT The present work describes the purification and characterization of peroxidase from the medicinal plant, Amsonia orientalis, for the first time. The activity recovery for peroxidase was 162% with 12.5-fold purification. Optimal purification parameters were 20% (w/v) (NH4)2SO4 saturation at pH 6.0 and 25°C with 1.0:1.0 (v/v) ratio of crude extract to t-butanol ratio for 30 min. The molecular mass of the enzyme was found to be ca. 59 kDa. Peroxidase showed Km values of 1.88 and 2.0 mM for pyrogallol and hydrogen peroxide, respectively. FeSO4, CuSO4, HgCl2, MnSO4 and MgSO4 did not inhibit the enzyme activity.

Separation of catalase from Amsonia orientalis with single step by aqueous two-phase partitioning system (ATPS)

ABSTRACT Catalase from Amsonia orientalis was purified by ATPS, and its efficiency was compared against hydrophobic interaction chromatography. Activity recovery and purification fold of purified catalase by ATPS were examined under varying experimental conditions. The effects of various factors such as type of phase-forming salts, (PEG) mass, with their different concentrations, pH and temperature effects on partitioning were investigated. The highest activity recovery (156%) and purification fold (8.67) of catalase were obtained in the ATPS system containing 10% (g/g) PEG4000, 15% (g/g) Na2SO4 at pH 6.0 and room temperature. In hydrophobic interaction chromatography, the enzyme has been purified 12.54-fold with 57.5% recovery. The molecular weight of catalase was determined as 75 kDa by SDS-PAGE.

Assessment of Macrophyte Plant Distribution and PAH Contamination in Selected Aquatic Habitats from an Industrialized City; Kocaeli, Turkey

Abstract The macrophyte plant distribution in some aquatic habitats and their availability for monitoring the PAH contamination were investigated in Kocaeli Province of Turkey. Alisma plantago-aquatica L. was collected to evaluate polyaromatic hydrocarbon (PAH) contamination in four aquatic habitats located nearby or distant to the industrial facilities and populated city center. Concentrations of eight PAH congeners were measured in A. plantagoaquatica leaves using gas chromatography. PAH sources were estimated using the following ratios, Fluoranthene / (Fluoranthene + Pyrene), Benzo(a)anthracene / (Benzo(a) anthracene + Chrysene) and Anthracene / (Anthracene + Phenanthrene) and were found to be pyrogenic-sourced in all stations. Since the ratios of congeners indicate the pyrogenic contamination, atmospheric deposition can be considered as the main pathway for PAH transportation. The highest ΣPAH concentration (798 μg kg-1) was measured in the nearest station (Bıçkıdere Dam) to the city center and highway, while the lowest concentration (183 μg kg-1) was determined in the Tahtalı Dam, which is relatively distant from the industrial facilities, dense population and motorways. Present results indicate that incomplete combustion of grass, wood and coal, as well as recreational and agricultural implementations and vehicular emissions, may cause pyrogenic PAH contamination. Also, broad basal leaves of A. plantago-aquatica can be considered as sampling material in further biomonitoring studies.

PAH and PCB Levels in Malva sylvestris L.Specimens Collected from Kocaeli, Turkey

Abstract: In this study, polycyclic aromatic hydrocarbon (PAH) and polychlorinated biphenyl (PCB) contaminations in the leaf, stem and root tissues of common mallow (Malva sylvestris L.) were investigated by using gas chromatography to give an insight into the bioaccumulation of these persistent pollutants. The sampling stations are located in the Dilovası and İzmit Districts of Kocaeli Province in Turkey. Total PAH concentrations varied between 10.44 and 61.15 pg g-1 dw (dry weight). The most dominant PAH congeners were Acenaphthene and Acenaphthylene which are low molecular weight. Total PCB concentrations were found to be between 326.79 and 4496.42 pg g-1 dw. PCB 66, PCB 110, PCB 153 and PCB 180 were found to be the most dominant congeners. Detected concentrations in root tissues showed the plant’s ability in accumulating these pollutants. Therefore, these findings suggest that Malva sylvestris can reflect the contamination levels which might be used to monitor soil and ecological pollution levels caused by these persistent pollutants.