Determination of some heavy metals and mineral nutrients of bay tree (Laurus nobilis L.) in Bartin city, Turkey

Concentrations of Al, Cd, Cu, Ni, and Pb in Laurus nobilis L. were examined for assessment of the impact of heavy metal exposure during winter periods, since these metals have the highest toxic potential. In this study, leaf (washed and unwashed), bark and branch samples of L. nobilis and soil samples were collected from 13 different localities, belonged to three stations. In conjunction with analyzing impact of the heavy metal exposure on the city using L. nobilis as a biomonitoring tool, the uptake and composition of mineral nutrients of L. nobilis were also investigated for determining the effects of heavy metals on mineral nutrition metabolism of the plant. The heavy metal and mineral nutrient concentrations of the collected samples were measured by using ICP-OES. The obtained data was analyzed with SPSS statistics program. As a result of measurements, the lowest and highest heavy metal accumulations and the amount of mineral nutrients measured in plants were as follows; Al (14.69-122.44 mg/kg d. wt), Cd (0.23-0.89 mg/kg d. wt), Cu (1.64-14.25 mg/kg d. wt.), Ni (0.001-0.45 mg/kg d. wt.), Pb (2.06-5.28 mg/kg d. wt.) and B (1.04- 6.67 mg/kg d. wt.), Ca (1195.34-4919.03 mg/kg d. wt.), Fe (17.13-203.25 mg/kg d. wt.), K (538.99-3778.37 mg/kg d. wt.), Mg(48.1-268.5 mg/kg d. wt.), Na (24.91-77.43 mg/kg d. wt.) and Zn (4.75-15.74 mg/kg d. wt.). According to the experimental data, the volume of the air pollution was analyzed and found significant in the city. Also, it was noticed that the metabolism of mineral nutrients of L. nobilis was altered by heavy metals. Finally, it was proved that L. nobilis is a suitable organism to be used as a biomonitoring tool for conducting research on heavy metal pollution

Mineral element uptake status of endemic Isoetes anatolica Prada & Rolleri populations from Bolu-Turkey

Isoetes genus is commonly known as the "quillworts" and considered to be "fern allies". There are about 200-250 species, with a cosmopolitan distribution but often scarce to rare. Isoetes genus members often grow in extremely sensitive aquatic environments such as temporary ponds, streams and lakes. They are therefore good indicators of environmental quality. Isoetes anatolica Prada & Rolleri is an endemic plant grows on calcareous sediment/soil on the edges of seasonal ponds located in a mountainous area near the southern coast of the Black Sea at 1400 m above sea level at Bolu, Turkey. In this study, mineral element uptake statuses of I. anatolica populations were studied on the background of plant-sediment/soil-water interactions. The study materials were collected from the place where this narrow endemic species only lives in the world (Abant Region, Bolu/Turkey) by using standard methods and plant and sediment/soil mineral element measurements (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, Ni and Zn) were done. ICP-OES was employed for the measurements during the study. Interrelations between mineral element contents in the sediment/soil, water and plant were discussed. The data revealed that I. anatolica is capable of accumulating considerable amounts of certain mineral elements (B, Ca, Mn and Na).Marmara University, Commission of Scientific Research Project (FEN-D-040712-0291

COMPARATIVE ANALYSIS OF MATURE AND PREPROPROTEIN FORM OF THIONINS IN SOME PLANT SPECIES; BIOINFORMATICS APPROACHES

WOS: 000471836900075Thionins are one of the most important antimicrobial peptides in broad-range plant defense. A number of studies are present regarding the structural and biological role of mature thionins but preproprotein forms of these molecules have not been extensively studied. Thus, this study aimed to comparatively analyze a total of 56 thionin preproprotein sequences from 14 different plant species. Analyses of primary, secondary and tertiary structures of these forms revealed that preproproteins with "gamma-thionin domain" were relatively shorter and more basic than proteins with "thionin domain" structure. In addition, members of "thionin domain" were more similar to each other than that of "gamma-thionin domain" forms. Sub-cellular localizations of these forms were predicted as extracellular. Structural superposition of precursor and mature thionins showed that a large portion of precursor sequences are cleaved to form a functional protein. Although precursor forms demonstrated the significant structural divergence in modelled species, functional mature forms showed a structural pattern in alpha-helices; two alpha-helix proteins included the "thionin domain" family while one a-helix proteins contained the "gamma-thionin domain" family. Results of this study will become valuable theoretical knowledge and provide insight in terms of further understanding the formation of mature functional thionins thereby their biological roles

Comparative analyses of phytochelatin synthase (PCS) genes in higher plants

Ozyigit, Ibrahim Ilker/0000-0002-0825-5951WOS: 000475893100001Plants employ various defence strategies to ameliorate the effects of heavy metal exposures, leading to re-establishment of metal homeostasis. One of the strategies includes the biosynthesis of main heavy metal detoxifying peptides phytochelatins (PCs) by phytochelatin synthase (PCS). In the present study, 14 PCS homologues were identified in the genomes of 10 selected plants. The size of these PCSs was 452-545 amino acid residues, with characteristic phytochelatin and phytochelatin_C domains. The N-terminal site of the proteins is highly conserved, whereas the C-terminal site is less conserved. Further, the present study also identified fully conserved Cys residues involved in heavy metal binding reported earlier. In addition, other preserved cysteines, with minor substitutions Cys(C)-> Ser(S) or Tyr(Y) or Trp(W), were also identified in the PCS sequences that might be associated with metal binding. The reported catalytic triad residues from Arabidopsis, Cys56, His162 and Asp180, are all conserved at the respective sites of PCSs. A clear monocot/dicot separation was revealed by phylogenetic analysis and was further corroborated by the exon-intron organisations of the PCS genes. Moreover, gene ontology terms, co-expression network, cis-regulatory motif and miRNA analyses indicated that the complex as well as dynamic regulation of PCSs has significant involvement in different metabolic pathways associated with signalling, defence, stress and phytohormone, in addition to metal detoxification. Moreover, variations in protein structure are suggested to confer the functional divergence in PCS proteins