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Öğe Ağır Metal Kirliliğinin Belirlenmesinde Biyomonitör Bitkilerin Rolü(Düzce Üniversitesi, 2024) Meral, Alperen; Torun, HülyaEndüstrileşmenin kaçınılmaz sonuçlarından olan kirlenme bütün dünyada en büyük problemlerden birisi haline gelmiştir. Gerekli tedbirler alınmadığı takdirde, çok uzak olmayan bir gelecekte, biyolojik dengenin bozulacağı, yerkürenin yaşanmaz hale geleceği muhakkaktır. Bu zorluğun üstesinden gelmek için metallere duyarlı bitkilerin biyomonitor olarak kullanılması kabul görmüştür. Böylece biyomonitör bitkilerin toksik metal analizleri yapılarak toprak, su ve havadaki toksik metal düzeyleri hakkında bilgi alınabilmektedir. Bu sayede, bitkisel organizmaya ilişkin biyomonitor türler eser elementlerin atmosferdeki konsantrasyonlarını araştırmak için kullanılmaktadır. Bu çalışmada trafik yoğunluğu, sanayileşme ve antropojenik etkiler gibi farklı kaynakların oluşturmuş olduğu ağır metal konsantrasyonlarının izlenmesinde 59 farklı alandan toplanan bitkilerin biyomonitör olarak kullanılabilme potansiyelleri araştırılmıştır. Örneklem alalar seçilirken kent kır farkının gözetilmiş ve farklı antropojen etkiler altında ağır metal miktarlarının değişimine bakılmıştır. Araziden toplanan bitkilerde Fe, Cu, Cr, Mn, Pb, Zn, Ni ve Al analizleri yapılmış ve araştırmaya dahil edilmiştir. Araştırma Trabzon İli sınırları içerisinde 3 kent ve 3 kır olmak üzere 6 lokasyonda gerçekleştirilmiştir. Analizler sonucunda gruplar arasındaki farkların belirlenebilmesi için One-Way ANOVA testi yapılmıştır. Yapılan istatistikî analizlere bakıldığında Cu ve Zn değerleri arasında lokasyon bazında anlamlı bir farklılık görülememişken diğer parametrelerde lokasyon bazında anlamlı farklılıklar gözlemlenmiştir.Öğe Antioxidant Defense System in Borago officinalis L. under Drought Stress(2021) Eroğlu, Engin; Torun, HülyaDrought is one of the main abiotic stress factor that limits plant growth and development. Droughtstress effects on Borago officinalis L. (borage) plants in terms of physiological and antioxidant responses havebeen evaluated in this study. In parallel with this purpose, relative growth rate (RGR), leaf relative watercontent (RWC), osmotic potential, chlorophyll fluorescence (Fv/Fm), lipid peroxidation, hydrogen peroxide($H_2O_2$) level, superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) andglutathione reductase (GR) activities were determined under drought treatment in a controlled greenhouse.RGR, RWC and osmotic potential were significantly decreased, while lipid peroxidation expressed thiobarbutiricacid reactive substances (TBARS) and $H_2O_2$ contents were increased under drought stress. On the other hand,significant increases in POX, CAT, APX and GR activities did not prevent the increase in lipid peroxidation. Tothe best of our knowledge, this is the first study conducted on the enzymatic antioxidants of the defensesystem of Borago officinalis L. under drought stress.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 Cephalaria duzceënsis N. Aksoy & R. S. Göktürk ve Seseli resinosum Freyn & Sint. Endemik Taksonlarının Morfolojik ve Fizyolojik Özellikleri ile Bitkilendirmede Kullanılabilme Potansiyelleri(Düzce Üniversitesi, 2020) Aydın, Harun; Torun, Hülya; Eroğlu, EnginEndemik bitkiler sahip oldukları nadir bulunma özelliklerinin yanı sıra estetik özellikleri ile peyzaj mimarlığı çalışmaları için önemli bitki grubunu oluşturmaktadır. Bitkilerin sahip oldukları estetik özellikler ve bitkilendirme çalışmalarında ortaya koydukları değer ile tasarımın ekolojik boyutu olan bitkilerin yaşadıkları ortamda uygun olmayan çevre koşullarına uyum sağlayarak gösterdikleri tolerans doğrudan ilişkilidir. Düzce’de bulunan ve Karadeniz Bölgesi için endemik bir tür olan Seseli resinosum Freyn & Sint. (Batı Karadeniz horozgözü) ve yalnızca Düzce ili sınırları içerinde yayılış gösteren Cephalaria duzceënsis N. Aksoy & R. S. Göktürk (Düzce pelemir otu) bitkilerinin kullanıldığı bu çalışmanın amacı, her iki türün peyzaj mimarlığında kullanımlarını estetik, fonksiyonel ve ekolojik potansiyelleri açısından belirlemektir. Bu amaç doğrultusunda, bitkilerin mevsimsel değişim potansiyelleri, yayılış gösterdikleri habitatlar düzeyinde bir yıl boyunca incelenmiştir. Bitkilerin yaprak, çiçek, sürgün, meyve gibi estetik özelliklerinin yanı sıra yaşam ortamlarındaki sosyobilite, yayılış, yaşam formu gibi bitki sosyolojisi özellikleri de incelenmiştir. Ayrıca, bitkilerin verimini önemli ölçüde sınırlayan iki önemli abiyotik stres olan kuraklık ve tuzluluk altında yaprak boy, yaş ve kuru ağırlığı gibi büyüme parametrelerindeki değişimler de ortaya konulmuştur. Sonuç olarak, bitkilerin peyzaj mimarlığında kullanım potansiyelleri her iki bitkinin ekolojik koşullarının kentsel adaptasyon özellikleri de dikkate alınarak oluşturulmuştur. Her iki endemik türün de çiçek estetikleri ön plana çıkarken Seseli resinosum sahip olduğu herdem yeşil yaprak yapısı ile bitki kompozisyonlarındaki renk sürekliliğine katkı sunmaktadır. Ayrıca, kuraklık ve tuz stresi koşullarına karşı iki endemik türün de biyokütlesinde değişim belirlenmiş olup S. resinosum’un tuz, C. duzceënsis’in ise kuraklık stresine toleransının yüksek olduğu belirlenmiştir.Öğe Cephalaria duzceënsis N. Aksoy & R. S. Göktürk ve Seseli resinosum Freyn & Sint. Endemik Taksonlarının Morfolojik ve Fizyolojik Özellikleri ile Bitkilendirmede Kullanılabilme Potansiyelleri(Düzce Üniversitesi, 2020) Aydın, Harun; Torun, Hülya; Eroğlu, EnginEndemik bitkiler sahip oldukları nadir bulunma özelliklerinin yanı sıra estetik özellikleri ile peyzaj mimarlığı çalışmaları için önemli bitki grubunu oluşturmaktadır. Bitkilerin sahip oldukları estetik özellikler ve bitkilendirme çalışmalarında ortaya koydukları değer ile tasarımın ekolojik boyutu olan bitkilerin yaşadıkları ortamda uygun olmayan çevre koşullarına uyum sağlayarak gösterdikleri tolerans doğrudan ilişkilidir. Düzce’de bulunan ve Karadeniz Bölgesi için endemik bir tür olan Seseli resinosum Freyn Sint. (Batı Karadeniz horozgözü) ve yalnızca Düzce ili sınırları içerinde yayılış gösteren Cephalaria duzceënsis N. Aksoy R. S. Göktürk (Düzce pelemir otu) bitkilerinin kullanıldığı bu çalışmanın amacı, her iki türün peyzaj mimarlığında kullanımlarını estetik, fonksiyonel ve ekolojik potansiyelleri açısından belirlemektir. Bu amaç doğrultusunda, bitkilerin mevsimsel değişim potansiyelleri, yayılış gösterdikleri habitatlar düzeyinde bir yıl boyunca incelenmiştir. Bitkilerin yaprak, çiçek, sürgün, meyve gibi estetik özelliklerinin yanı sıra yaşam ortamlarındaki sosyobilite, yayılış, yaşam formu gibi bitki sosyolojisi özellikleri de incelenmiştir. Ayrıca, bitkilerin verimini önemli ölçüde sınırlayan iki önemli abiyotik stres olan kuraklık ve tuzluluk altında yaprak boy, yaş ve kuru ağırlığı gibi büyüme parametrelerindeki değişimler de ortaya konulmuştur. Sonuç olarak, bitkilerin peyzaj mimarlığında kullanım potansiyelleri her iki bitkinin ekolojik koşullarının kentsel adaptasyon özellikleri de dikkate alınarak oluşturulmuştur. Her iki endemik türün de çiçek estetikleri ön plana çıkarken Seseli resinosum sahip olduğu herdem yeşil yaprak yapısı ile bitki kompozisyonlarındaki renk sürekliliğine katkı sunmaktadır. Ayrıca, kuraklık ve tuz stresi koşullarına karşı iki endemik türün de biyokütlesinde değişim belirlenmiş olup S. resinosum’un tuz, C. duzceënsis’in ise kuraklık stresine toleransının yüksek olduğu belirlenmiştir.Öğe Cobalt+Salt-Stressed Salvia officinalis: ROS Scavenging Capacity and Antioxidant Potency(2019) Torun, HülyaSalvia officinalis L. (Lamiaceae) is one of the most widespread herbal species used in the food processing industry and for culinary and medicinal purposes. This work aimed to investigate changes in plant growth, water content, lipid peroxidation, H2O2, proline, and enzymes related to reactive oxygen species (ROS) detoxification including superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR). Phenolic contents and antioxidant capacity values such as ferric ion reducing antioxidant power (FRAP), cupric ion reducing antioxidant capacity (CUPRAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were studied under stress conditions of salt, cobalt and a combination of the two. No significant differences were found in relative water content and chlorophyll fluorescence under salt, cobalt and their combination. However, the osmotic potential and relative growth rate were enhanced with salt+cobalt compared to salt-treated plants. Salt and cobalt individually stimulated high antioxidant activity. High APX and GR activities were associated with the high proline accumulation in the sage plants under the combined effect of salt+cobalt. The combination decreased lipid peroxidation (TBARS), while H2O2 content was increased. This increase with the combined salt+cobalt effect may be associated with the decrease in CAT activity. Moreover, a strong correlation was found between TPC and TF content and antioxidant capacity measured via FRAP, CUPRAC and DPPH. The TPC, TF and antioxidant capacity values also increased under the salt+cobalt combination, suggesting an increase in antioxidant content in the sage leaves. Therefore, the combination of salt and cobalt improved the stress tolerance of S. officinalis.Öğe CobaltSalt-Stressed Salvia officinalis: ROS Scavenging Capacity and Antioxidant Potency(2019) Torun, HülyaSalvia officinalis L. (Lamiaceae) is one of the most widespread herbal species used in the food processing industry and for culinary and medicinal purposes. This work aimed to investigate changes in plant growth, water content, lipid peroxidation, H2O2, proline, and enzymes related to reactive oxygen species (ROS) detoxification including superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR). Phenolic contents and antioxidant capacity values such as ferric ion reducing antioxidant power (FRAP), cupric ion reducing antioxidant capacity (CUPRAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging were studied under stress conditions of salt, cobalt and a combination of the two. No significant differences were found in relative water content and chlorophyll fluorescence under salt, cobalt and their combination. However, the osmotic potential and relative growth rate were enhanced with saltcobalt compared to salt-treated plants. Salt and cobalt individually stimulated high antioxidant activity. High APX and GR activities were associated with the high proline accumulation in the sage plants under the combined effect of saltcobalt. The combination decreased lipid peroxidation (TBARS), while H2O2 content was increased. This increase with the combined saltcobalt effect may be associated with the decrease in CAT activity. Moreover, a strong correlation was found between TPC and TF content and antioxidant capacity measured via FRAP, CUPRAC and DPPH. The TPC, TF and antioxidant capacity values also increased under the saltcobalt combination, suggesting an increase in antioxidant content in the sage leaves. Therefore, the combination of salt and cobalt improved the stress tolerance of S. officinalis.Öğe Combined efficiency of salicylic acid and calcium on the antioxidative defense system in two different carbon-fixative turfgrasses under combined drought and salinity(Elsevier, 2022) Torun, HülyaCombined stress effects are unique when compared to individual stress applications. As the subject has not been previously examined, the aim of this study was to investigate the role of salicylic acid (SA) and calcium (Ca) as signaling molecules under combined drought and salt stresses on two different carbonfixative turfgrasses, Lolium perenne L. (perennial ryegrass; C3) and Cynodon dactylon (L.) Pers. (Bermuda grass; C4). Twenty-one days after germination, PEG6000 (5%) and NaCl (150 mM) were applied simultaneously as a combined drought and salinity (DS) treatment. Before starting the treatment, half of the seedlings were treated with SA (0.5 mM) solution for 24 h; Ca (5 mM) was also applied simultaneously to the SA-treated groups. Combined drought and salt stresses caused substantial decreases in leaf growth parameters, relative water content, and osmotic potential in both cultivars, whereas lipid peroxidation (TBARS), hydrogen peroxide (H2O2), and electrolyte leakage increased. However, the deleterious effect of the combined stress was much more pronounced in Bermuda grass. On the other hand, activities of superoxide dismutase (SOD), peroxidase (PDX), ascorbate peroxidase (APX), and glutathione reductase (GR) in perennial ryegrass and only GR in Bermuda grass were reduced by DS. Moreover, Na accumulation was greater in perennial ryegrass (33.9-fold) than in Bermuda grass (11.1-fold). Under stress, simultaneous SA+Ca application was more effective on the recovery potential of Bermuda grass than on that of perennial ryegrass, with enhanced growth as well as increased proline, K, Mg, and Ca contents, and retained RWC. However, the SA+Ca treatment for the perennial ryegrass under DS significantly enhanced the antioxidant defense activities of SOD, PDX, APX, and GR as well as increasing the TBARS and H2O2 content, compared with plants subjected to DS alone. Taken together, these results indicated that simultaneous application of SA+Ca could play a positive regulatory role, which in turn could improve the double-stress tolerance of turfgrasses. (C) 2021 SAAB. Published by Elsevier B.V. All rights reserved.Öğe Combined Salt and Nickel Stress Impact on ROS Generation and Antioxidant Enzymes Activities of Lemon Balm (Melissa officinalis)(2019) Torun, HülyaPlants acclimation to stress is a complex process and this complexity increase with simultaneous subjection to two or more abiotic stress. Salinity and excess accumulation of nickel are growth and development restricted abiotic stress agents. The aim of the present study was to determine the antioxidant defense system responses of Melissa officinalis (lemon balm) to salinity, nickel and their combinations. Growth, leaf osmotic potential, chlorophyll fluorescence, relative water content (RWC), lipid peroxidation, H2O2 and proline content and antioxidant enzyme activities were determined under these stress conditions. Growth and leaf osmotic potential negatively affected due to the combined effect of salt and nickel. All three stress treatments did not show any significant change on RWC and chlorophyll fluorescence in lemon balm. H2O2 content and lipid peroxidation of combined stress had greater than salt and nickel alone. Total activities of ascorbate peroxidase (APX) and glutathione reductase (GR) were increased with salt, nickel and their combinations. Moreover, the reduction in superoxide dismutase (SOD), peroxidase (POX) and catalase (CAT) activities resulted in higher lipid peroxidation and H2O2 content under the combined stress. To the best of our knowledge, this is the first study conducted on the activities of antioxidant defense enzymes of lemon balm under salinity and nickel combinations.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 Ecophysiological responses of endemic Cephalaria duzceensis to drought and salt stress(Springer, 2022) Torun, Hülya; Aydın, HarunEndemic plants attract attention for their increasing potential for genetic biodiversity, an important phenomenon in all aspects of science. Little is known about the ability of the endangered Turkish endemic plant Cephalaria duzceensis to generate/remove reactive oxygen species or to adapt its biochemical responses in drought and saline environments. Consequently, changes in growth, relative water content (RWC), chlorophyll fluorescence (Fv/Fm), osmotic potential, hydrogen peroxide (H2O2) and proline contents, lipid peroxidation, and antioxidant enzymes were measured under drought (0, 5, 10, 15% PEG 6000) and salt (0, 75, 150, 225 mM NaCl) stresses. Salt-induced RWC, Fv/Fm, osmotic potential reduction, and lipid peroxidation were enhanced, suggesting that C. duzceensis is more sensitive to salinity than to drought. However, interestingly, growth increased under both. Although the increase in H2O2 content was greater under drought stress, aside from ascorbate peroxidase, no antioxidant enzyme activity increase was observed under salt stress. Conversely, the increase in peroxidase, ascorbate peroxidase, and catalase activity observed under drought may be related to the better growth performance, less Fv/Fm reduction, better water maintenance, and lower osmotic potential of C. duzceensis. These results strongly suggest that this endemic plant exhibits moderate drought tolerance and that salt stress has a more detrimental effect on C. duzceensis than drought stress.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 Kuraklığın Ebegümeci (Malva sylvestris L.) Bitkisinin Su Durumu, Büyümesi ve Antioksidan Sistem Üzerine Etkisi(Duzce University, 2024) Şahin, Seda; Torun, HülyaEbegümeci (Malva sylvestris L.), Malvaceae familyasına üye, çiçekleri mor çizgili pembe renkli, tıbbi aromatik bir bitki olup gıda ve sağlık alanlarında oldukça yaygın kullanılmaktadır. Bu çalışmanın amacı, kuraklık stresinin ebegümeci bitkisinin büyümesi, su içeriği ve antioksidan savunma sistemi enzimleri üzerine etkilerini incelemektir. Bu doğrultuda, 21 gün kuraklığa maruz bırakılan bitkinin yapraklarında nisbi büyüme, osmotik potansiyel, nisbi su içeriği, lipid peroksidasyonu, hidrojen peroksit içeriği ile süperoksit dismutaz (SOD), peroksidaz (POX), katalaz (CAT), askorbat peroksidaz (APX) ve glutatyon redüktaz (GR) antioksidan enzim aktiviteleri ölçülmüştür. Kuraklık stresi altındaki bitkilerle stres uygulaması olmayan bitkiler kıyaslandığında, büyüme oranı, nisbi su içeriği, osmotik potansiyel önemli ölçüde azalmıştır. Ayrıca, lipid peroksidasyonu ve hidrojen peroksit miktarları kuraklık uygulaması ile artmıştır. Bitkinin savunma sistemi kuraklık stresi altında uyarılmış ve SOD, POX, CAT, APX ve GR aktivitelerinde artış kaydedilmiştir. Bu çalışmada, kuraklık stresine maruz kalan ebgümecinde antioksidan savunma sisteminin etkinliği belirlenmiştir.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 Physicochemical and Antioxidant Responses of St. John's Wort (Hypericum perforatum L.) under Drought Stress(2021) Eroğlu, Engin; Usta, Elmas Ülkühan; Torun, Hülya; Yalçın, VesileThis study investigated the effects of drought stress on the physiological and biochemical responses of the medicinal and aromatic plant Hypericum perforatum (St. John’s Wort). Changes were determined in leaf length, relative water content (RWC), osmotic potential, chlorophyll fluorescence (Fv/Fm), lipid peroxidation (TBARS), hydrogen peroxide ($H_2O_2$), and proline content as well as in the antioxidant system enzyme activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), and glutathione reductase (GR). These responses were examined in relation to the tolerance of drought stress in H. perforatum. Ninety-dayold seedlings were subjected to drought for three weeks. The physiological parameters of leaf length, RWC, Fv/Fm, and osmotic potential were reduced under drought. The $H_2O_2$, TBARS, and proline levels were increased significantly under drought stress. Moreover, the proline content increase was greatly pronounced (25.9-fold) compared to the control groups. The high accumulation of proline may have resulted from the 83.8% leaf RWC still remaining under drought stress. On the other hand, the SOD, CAT, and GR enzyme activities were enhanced, whereas the POX and APX activities were reduced. The results indicate that improved tolerance to drought stress in H. perforatum plants may be accomplished through increased capacity of the antioxidative defense system.Öğe Physiological and Antioxidative Responses of Endemic Plant Seseli resinosum Freyn & Sint. to Drought Stress(2021) Torun, Hülya; Aydın, HarunSeseli resinosum Freyn & Sint. is an endemic perennial plant of rocky habitat of the Western Black Sea region of Turkey. To understand drought responses and tolerance mechanism of Seseli resinosum Freyn & Sint., relative water content (RWC), chlorophyll fluorescence, proline accumulation, lipid peroxidation (TBARS), hydrogen peroxide (H2O2) content and changes in antioxidant enzymes were assayed in polyethylene glycol (PEG) 6000 (5, 10 and 15%) induced drought stress in the present study. Leaf RWC maintained unchanged, while chlorophyll fluorescence reduced with a high PEG level (15%). Additionally, H2O2 and proline accumulation were determined with the increase of PEG application, but no increase in TBARS was determined. Moreover, the increment in H2O2 content under drought was accompanied by an increase glutathione reductase, catalase and superoxide dismutase activities. On the other hand, PEG-induced drought stress caused a reduction in peroxidase and ascorbate peroxidase activities. These results suggest that endemic Seseli resinosum Freyn & Sint. plant has an efficient drought tolerance, as displayed by enhanced antioxidant enzyme activities maintaining water status under drought conditions. In this study, important information about physiological and antioxidative responses of endemic Seseli resinosum Freyn & Sint. was revealed for the first time.Öğe Physiological and Antioxidative Responses of Endemic Plant Seseli resinosum Freyn & Sint. to Drought Stress(Düzce Üniversitesi, 2021) Torun, Hülya; Aydın, HarunSeseli resinosum Freyn Sint. is an endemic perennial plant of rocky habitat of Western Black Sea region of Turkey. To understand drought responses and tolerance mechanism of Seseli resinosum, relative water content (RWC), chlorophyll fluorescence, lipid peroxidation (TBARS), hydrogen peroxide (H2O2), proline content and changes in antioxidant enzymes were assayed in polyethylene glycol (PEG) 6000 (5, 10 and 15%) induced drought stress in the present study. Leaf RWC maintained unchanged, while chlorophyll fluorescence reduced with high level of PEG (15%). Additionally, H2O2 and proline accumulation were determined with the increase of PEG application, but no increase in the amount of TBARS was determined. Moreover, the increment in H2O2 content under drought was accompanied by increased in superoxide dismutase, catalase and glutathione reductase activities. On the other hand, PEG-induced drought stress caused a reduction in peroxidase and ascorbate peroxidase activities. These results suggest that endemic Seseli resinosum plant have an efficient drought tolerance, as displayed by enhanced antioxidant enzyme activities with maintaining water status under drought conditions. In this study, important information about physiological and antioxidative responses of endemic Seseli resinosum was revealed for the first time.Öğe Şeker Otu (Stevia rebaudiana Bertoni) Bitkisinde Kuraklık Stresinin Fizyolojik ve Biyokimyasal Etkileri(Düzce Üniversitesi, 2022) Yalçın, Vesile; Torun, Hülya; Eroğlu, Engin; Usta, Elmas ÜlkühanKuraklık son yıllarda endişe verici bir şekilde artmakta olup tarımsal ürünlerin verimliliğini sınırlandırmaktadır. Bu durum, kurak koşullara dayanıklı bitkilerin tespit edilmesine yönelik araştırmaların önemini artırmıştır. Bu çalışmada, Stevia rebaudiana Bertoni bitkisine ait iki çeşidin (Yalova ve STF-4) kuraklık stresi altında fizyolojik ve biyokimyasal tepkileri araştırılmıştır. Bitkiler kontrollü sera koşullarında 3 ay boyunca yetiştirilmiş ve sonrasında 3 hafta boyunca kuraklığa maruz bırakılmıştır. Üç hafta sonunda hasat edilen bitkilerden yaprak uzunluğu, ozmotik potansiyel, nisbi su içeriği (RWC), klorofil floresansı (Fv/Fm), prolin miktarı, hidrojen peroksit (H2O2) miktarı ve lipid peroksidasyonu seviyesi ölçülmüştür. S. rebaudiana bitkisinin her iki çeşidinde de kuraklık stresi altında kontrol grubundaki bitkiler ile kıyaslandığında yaprak uzunluğunda azalma belirlenirken en çok azalma Yalova çeşidinde (%25,7) saptanmıştır. Bununla birlikte, her iki çeşit de kuraklık stresi altında su durumlarını korumuşlardır. Fv/Fm değeri STF-4 çeşidinde kuraklıktan etkilenmezken Yalova çeşidinde kontrole oranla düşüş göstermiştir. Prolin miktarında ise çeşitler arasında fark kaydedilmiştir. Kurak koşullar altında STF-4 çeşidinde prolin miktarında değişim gözlenmezken Yalova çeşidinde %42,9 artış meydana gelmiştir. Diğer taraftan, kuraklık stresi, yapraklardaki lipid peroksidasyon seviyesini önemli ölçüde arttırmıştır. Bu artış, Yalova çeşidinde %41,2 iken STF-4 çeşidinde %21,1 olarak belirlenmiştir. İki çeşit arasında kuraklık stresine karşı farklı tepki H2O2 içeriğinde gözlenmiştir. Kuraklık stresi altında H2O2 miktarı Yalova çeşidinde %42,7 oranında azalırken STF-4 çeşidinde %5,5 artmıştır. Sonuç olarak, S. rebaudiana bitkisinin STF-4 çeşidinin ölçülen parametreler ışığında kuraklığa daha toleranslı olduğu ortaya konulmuştur.
