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Öğe Bog bilberry phenolics, antioxidant capacity and nutrient profile(Elsevier Sci Ltd, 2016) Çolak, Nesrin; Torun, Hülya; Gruz, Jiri; Strnad, Miroslav; Gutierrez, Isidro Hermosin; Ayaz, Sema Hayırlıoğlu; Ayaz, Faik AhmetPhenolics and nutrient profiles of bog bilberry (Vaccinium uliginosum L.) collected from high mountain pastures in northeast Anatolia (Turkey) were examined for the first time in this study. The major soluble sugar identified in the berry was fructose, following by glucose, and the main organic acid identified was citric acid, followed by malic acid. Eleven phenolic acids and 17 anthocyanin 3-glycosides were identified and quantified. Caffeic acid in the free and glycoside forms and syringic acid in the ester form were the major phenolic acids, and the major individual anthocyanin present in the berry was malvidin 3-glucoside (24%). The highest total phenolics and anthocyanin contents were obtained from the anthocyanin fraction in conjunction with the highest antioxidant capacity, followed by the polyphenolic and aqueous fractions, FRAP, ORAC and DPPH, in that order. Our findings can be used to compare bog bilberry with other Vaccinium berries and to help clarify the relative potential health benefits of different berries. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Comparison of Phenolics and Phenolic Acid Profiles in Conjunction with Oxygen Radical Absorbing Capacity (ORAC) in Berries of Vaccinium arctostaphylos L. and V. myrtillus L.(De Gruyter Open Ltd, 2016) Çolak, Nesrin; Torun, Hülya; Gruz, Jiri; Strnad, Miroslav; Subrtova, Michaela; İnceer, Hüseyin; Ayaz, Faik AhmetCaucasian blueberry (Vaccinium arctostaphylos L.) and bilberry (V. myrtillus L.), both native to Turkey, were evaluated for their total phenolics (TP) and anthocyanin (TAC) contents. Individual compositions of free phenolic acids and phenolic acids liberated from ester and glycoside forms were analyzed using UPLC-MS/MS. Berry extracts of each species were separated into three different fractions (sugar/acid, polyphenolic and anthocyanin) by solid phase extraction (SPE). The anthocyanin fractions of each species had the highest level of TP and TAC contents and ORAC values. Each species contained 10 phenolic acids representing each fraction, but in different quantities. The phenolic acids liberated from the esters and glycoside forms were caffeic acid and p-coumaric acid. The fractions containing phenolic acids liberated from ester and glycoside forms had a higher antioxidant capacity than that from free phenolic acids. The data suggest that both berries have potential as good dietary sources of phenolic antioxidants.Öğe The Effects of Exogenous Salicylic Acid on Endogenous Phytohormone Status in Hordeum vulgare L. under Salt Stress(Mdpi, 2022) Torun, Hülya; Novak, Ondrej; Mikulik, Jaromir; Strnad, Miroslav; Ayaz, Faik AhmetAcclimation to salt stress in plants is regulated by complex signaling pathways involving endogenous phytohormones. The signaling role of salicylic acid (SA) in regulating crosstalk between endogenous plant growth regulators' levels was investigated in barley (Hordeum vulgare L. 'Ince'; 2n = 14) leaves and roots under salt stress. Salinity (150 and 300 mM NaCl) markedly reduced leaf relative water content (RWC), growth parameters, and leaf water potential (LWP), but increased proline levels in both vegetative organs. Exogenous SA treatment did not significantly affect salt-induced negative effects on RWC, LWP, and growth parameters but increased the leaf proline content of plants under 150 mM salt stress by 23.1%, suggesting that SA enhances the accumulation of proline, which acts as a compatible solute that helps preserve the leaf's water status under salt stress. Changes in endogenous phytohormone levels were also investigated to identify agents that may be involved in responses to increased salinity and exogenous SA. Salt stress strongly affected endogenous cytokinin (CK) levels in both vegetative organs, increasing the concentrations of CK free bases, ribosides, and nucleotides. Indole-3-acetic acid (IAA, auxin) levels were largely unaffected by salinity alone, especially in barley leaves, but SA strongly increased IAA levels in leaves at high salt concentration and suppressed salinity-induced reductions in IAA levels in roots. Salt stress also significantly increased abscisic acid (ABA) and ethylene levels; the magnitude of this increase was reduced by treatment with exogenous SA. Both salinity and SA treatment reduced jasmonic acid (JA) levels at 300 mM NaCl but had little effect at 150 mM NaCl, especially in leaves. These results indicate that under high salinity, SA has antagonistic effects on levels of ABA, JA, ethylene, and most CKs, as well as basic morphological and physiological parameters, but has a synergistic effect on IAA, which was well exhibited by principal component analysis (PCA).Öğe Exogenous melatonin ameliorates ionizing radiation-induced damage by modulating growth, osmotic adjustment and photosynthetic capacity in wheat seedlings(Elsevier France-Editions Scientifiques Medicales Elsevier, 2022) Kurt Çelebi, Aynur; Çolak, Nesrin; Torun, Hülya; Dosedelova, Vera; Tarkowski, Petr; Ayaz, Faik AhmetAs a multifunctional signal molecule, melatonin (N-acetyl-5-methoxytryptamine) plays many important roles in the regulation of plant growth and development. The effect of melatonin application on enhancing plant stress tolerance has been widely reported, but the ameliorative effect of exogenous melatonin treatment on plants exposed to ionization stress is still unknown. This study investigated the ameliorative effects of two types of melatonin treatment, pre-sowing priming (prMel) and application during growth (ptMel), in wheat (Triticum aestivum L.) seedlings exposed to different radiation doses (100, 200, 300 and 400 Gy) of radioactive cobalt (60Co) gamma rays as dry seeds. The growth parameters, photosynthetic pigments, chlorophyll fluorescence, osmotic potential with soluble sugars, fructans and proline contents were then examined. The results indicated that high doses of ionizing radiation (IR) led to decreases in plant growth, pigment contents, chlorophyll fluo-rescence ratios and osmotic potential. However, soluble sugar, fructan and proline contents increased under IR stress conditions. Both melatonin applications, but particularly prMel, enhanced the morphological parameters, preserved the photosynthetic machinery and regulated the osmotic adjustment of IR-stressed wheat seedlings. Taken together, the findings show that exogenously applied melatonin, particularly prMel, play a significant role in alleviating IR stress in wheat seedlings.Öğe Exogenous N-Acetylcysteine alleviates heavy metal stress by promoting phenolic acids to support antioxidant defence systems in wheat roots(Academic Press Inc Elsevier Science, 2019) Çolak, Nesrin; Torun, Hülya; Gruz, Jiri; Strnad, Miroslav; Ayaz, Faik AhmetN-acetylcysteine (N-Acetyl L-cysteine, NAC) is a thiol compound derived from the addition of the acetyl group to cysteine amino acid. NAC has been used as an antioxidant, free radical scavenger, and chelating agent for reducing the deleterious effects on plants of biotic and abiotic environmental stresses. It can also relieve heavy metal (HM) toxicity, although its alleviating mechanism remains unknown. In this study, we compared HM-stressed (Cu, Hg, Cd and Pb, 100 mu M each) wheat seedlings without NAC treatment and in combination with NAC (1 mM). In comparison to HMs alone, NAC treatment in combination with HMs (Cu, Cd, Hg and Pb, respectively) stimulated root growth (1.1-, 1.5-, 10.5- and 1.9-fold), and significantly increased fresh (1.3-, 1.5-, 4.3- and 1.4-fold) and dry (1.2-, 1.5-, 2.5- and 1.2-fold) mass. Combination treatment also led to significant reductions in HM concentrations (1.3-, 1.4-, 4- and 1.1-fold, respectively). GSH (1.1 - 1.8-fold), TBARS (1.4 - 2.7-fold) and H2O2 (1.6 - 1.8-fold) contents in treatment with HMs alone were significantly mitigated by the NAC combination. Some of the antioxidant enzyme activities increased or reduced by some HM treatments alone were stimulated by a combination of NAC with HMs, or remained unchanged or changed only insignificantly, supported by the phenolic pool of the plant. Ferulic, p-comaric and syringic acids were the major phenolic acids (PAs) in the roots in free, ester, glycoside and ester-bound forms, and their concentrations were increased by HM treatments alone, in comparison to the control seedlings, while PAs concentrations were relatively reduced by NAC in combination with HMs. These results indicate that NAC can alleviate HM toxicity and improve the growth of HM-stressed wheat seedlings by coordinated induction of the phenolic pool and the antioxidant defence system.Öğe Nutrient profiles of the hybrid grape cultivar 'Isabel' during berry maturation and ripening(Wiley, 2017) Kurt, Aynur; Torun, Hülya; Çolak, Nesrin; Seiler, Gerald; Ayaz, Sema Hayırlıoğlu; Ayaz, Faik AhmetBACKGROUND: The hybrid grape cultivar 'Isabel' (Vitis labrusca x V. vinifera) is widely grown in the Black Sea region of Turkey and constitutes an important part of the diet of its inhabitants. Phenological and ampelographic studies of the grape have previously been performed, but there are no data concerning nutrient composition. Its nutrient content needs to be investigated to ascertain its potential economic and nutritional uses in the region. RESULTS: The concentrations (range, g kg(-1) fresh weight) of major soluble sugars (fructose 2.08-79.70; glucose 3.71-66.74) increased and those of organic acids (tartaric acid 0.05-6.60; malic acid 2.38-9.92) decreased in the skin and pulp during ripening. The major fatty acid was linoleic acid in the skin (50.13), pulp (18.11) and seed (704), while the main minerals (dry weight) were potassium (2.70-19.70), followed by phosphorus (0.53-3.40) and calcium (0.42-5.90) in the parts. CONCLUSION: Berry maturation and ripening significantly influenced the concentrations of sugars and organic acids the most in the skin and pulp, but did not significantly affect the concentrations of fatty acids and minerals in the 'Isabel' grape. Our findings also suggest an optimal harvest time in terms of levels of the nutrients. (C) 2016 Society of Chemical IndustryÖğe Phenolic compounds and antioxidant capacity in different-colored and non-pigmented berries of bilberry (Vaccinium myrtillus L.)(Elsevier Science Bv, 2017) Çolak, Nesrin; Primetta, Anja K.; Riihinen, Kaisu R.; Jaakola, Laura; Gruz, Jiri; Strnad, Miroslav; Ayaz, Faik AhmetBilberries and their products are popular worldwide and represent a very interesting source of dietary antioxidants. Berries of eight different-colored and non-pigmented bilberry (Vaccinium myrtillus L.) samples from Finland were evaluated in terms of antioxidant capacity and total phenolic compounds (range, 220.06 - 3715.21 mg/100 g dw) and total monomeric anthocyanin (range, 206.18 - 867.52 mg/100 g dw) contents. Delphinidin (range, 5915.93-18108.39 mu g/g dw) was the major anthocyanin moiety, while sinapic acid was the major phenolic acid in the free form (range, 0.01 - 6.06 mu g/g dw), and p-coumaric acid in the ester (range, 26.39 - 110.78 mu g/g dw), glycoside (range, 15.83 - 57.73 mu g/g dw) and ester-bound (range, 2.32 - 14.20 mu g/g dw) forms. The white colored berry samples did not contain any anthocyanins, but the colored berries did contain them. Antioxidant capacity was much higher in colored (pink to blue/black) berry samples than in the white sample, and it was more related to the total phenolic concentration rather than to the anthocyanin concentration. This is the first time that these different-colored berry phenotypes of bilberry (V. myrtillus L.) have been analyzed within the same study.Öğe Timing-dependent effects of salicylic acid treatment on phytohormonal changes, ROS regulation, and antioxidant defense in salinized barley (Hordeum vulgare L.)(Nature Portfolio, 2020) Torun, Hulya; Novak, Ondrej; Mikulik, Jaromir; Pencik, Ales; Strnad, Miroslav; Ayaz, Faik AhmetCross-talk between exogenous salicylic acid (SA) and endogenous phytohormone pathways affects the antioxidant defense system and its response to salt stress. The study presented here investigated the effects of SA treatment before and during salt stress on the levels of endogenous plant growth regulators in three barley cultivars with different salinity tolerances: Hordeum vulgare L. cvs. Akhisar (sensitive), Erginel (moderate), and Kalayc (tolerant). The cultivars' relative leaf water contents, growth parameters, proline contents, chlorophyll a/b ratios, and lipid peroxidation levels were measured, along with the activities of enzymes involved in detoxifying reactive oxygen species (ROS) including superoxide-dismutase, peroxidase, catalase, ascorbate-peroxidase, and glutathione-reductase. In addition, levels of several endogenous phytohormones (indole-3-acetic-acid, cytokinins, abscisic acid, jasmonic acid, and ethylene) were measured. Barley is known to be more salt tolerant than related plant species. Accordingly, none of the studied cultivars exhibited changes in membrane lipid peroxidation under salt stress. However, they responded differently to salt-stress with respect to their accumulation of phytohormones and antioxidant enzyme activity. The strongest and weakest increases in ABA and proline accumulation were observed in Kalayc and Akhisar, respectively, suggesting that salt-stress was more effectively managed in Kalayc. The effects of exogenous SA treatment depended on both the timing of the treatment and the cultivar to which it was applied. In general, however, where SA helped mitigate salt stress, it appeared to do so by increasing ROS scavenging capacity and antioxidant enzyme activity. SA treatment also induced changes in phytohormone levels, presumably as a consequence of SA-phytohormone salt-stress cross-talk.Öğe TUZ STRESİ KOŞULLARINDA SALİSİLİK ASİDİN ZAMANA BAĞLI UYGULANMASININ ARPA (Hordeum vulgare L.) KÖKLERİNİN ANTİOKSİDAN SAVUNMA SİSTEMİ ÜZERİNE ETKİLERİ(2019) Torun, Hülya; Ayaz, Faik AhmetToprak tuzluluğu önemli ürün kayıplarına neden olan başlıca abiyotik stres tiplerinden biridir. Tuzluluk stresi esnasında bitkidegeliştirilen tolerans mekanizmalarını anlayabilmek, ürün verim ve kalitesindeki ciddi kayıpları azaltan tolerant çeşitlerin seçimive ıslahında önem arz etmektedir. Salisilik asit (SA), bitkilerde tuz stresi dahil pek çok abiyotik streste fizyolojik vebiyokimyasal süreçleri etkileyen önemli bir sinyal moleküldür. Bu çalışmada, SA’nın tuz stresi öncesinde ve stres süresinceuygulanmasının, arpa (Hordeum vulgare L. cv. Kalaycı, Erginel, Akhisar) çeşitlerinin köklerinde büyüme parametreleri, prolinmiktarı ve antioksidan savunma sistemi enzimlerinin (süperoksit dismutaz (SOD), peroksidaz (POX), katalaz (CAT), askorbatperoksidaz (APX), glutatyon redüktaz (GR)) aktivitelerini nasıl değiştirdiği incelenmiştir. Tuz stresi, arpanın her üç çeşidindede büyüme parametrelerinde azalmaya neden olmuştur. Strese karşı en tolerant çeşit Kalaycı, en hassas ise Akhisar olarakbelirlenmiştir. Ayrıca, SA’nın uygulama süresinin antioksidan savunma sistemi üzerindeki etkisi ortaya konulmuştur. Sonuçolarak, SA antioksidan savunma sistemini uyararak tuz stresinin sebep olduğu oksidatif hasarı azaltmıştır. Bu etki, SA’nınuygulama zamanına ve türün çeşitlerine göre farklılık göstermiştir. Özellikle stres öncesi uygulanan SA, tuz stresine karşı dahayüksek tolerans göstermiş ve çeşitler arasında bu etki daha çok Kalaycı çeşidinde gözlenmiştir.
