Articles by Sefer Demirbas
Journal of Agricultural Sciences (Tarim Bilimleri Dergisi), 2022
Salinity is affecting plant growth and development. Low concentration of hydrogen peroxide (H2O2)... more Salinity is affecting plant growth and development. Low concentration of hydrogen peroxide (H2O2) has shown to be effective against various stress factors. In this study, effect of different H2O2 priming methods on growth, physiological and biochemical parameters in three wheat varieties (NKÜ Lider, Sultan-95, and Tosunbey) under salt stress were investigated. Salt stress (0 and 160 mM NaCl) was applied gradually to 100 µM H2O2 applied (-H2O2: negative control, no application; H2O2: positive control, 100 μM H2O2 applied; 1xH2O2: 100 μM H2O2 applied one year ago; 2xH2O2: 100 μM H2O2 applied second time after one year) wheat seedlings. Biochemical results showed that the lowest H2O2 level was in NKÜ Lider variety and in-H2O2 and 1xH2O2 groups. The lowest thiobarbituric acid reactive substances (TBARS) level was in Tosunbey variety and 2xH2O2 group. The highest superoxide dismutase (SOD) activity was in NKÜ Lider variety, all H2O2 pre-treatment caused an increase in SOD activity and 2xH2O2 pre-treatment caused the highest SOD activity. However, H2O2 and TBARS levels increased in all application groups except 2xH2O2 group, while the H2O2 amount increased and TBARS level decreased in 2xH2O2 group. MnSOD was not detected in any groups. CuZnSOD increased in all groups except 2xH2O2 groups under salt stress in Sultan-95 variety compared to FeSOD. H2O2 pre-treatment better tolerated salt stress, and second-applied H2O2 pretreatment eliminated the stress and improved plant growth. In conclusion, it was determined that H2O2 re-pre-treatment to wheat seeds resulted in improvement of plant growth in tolerant varieties exposed to salt stress.
Tekirdag Namik Kemal University Institute of Natural and Applied Sciences
Die Bodenkultur: Journal of Land Management, Food and Environment
Summary The objective of this work was to investigate the levels of photosynthetic pigments, anti... more Summary The objective of this work was to investigate the levels of photosynthetic pigments, antioxidant enzyme activities (superoxide dismutase [SOD], catalase [CAT], peroxidase [POX], ascorbate peroxidase [APX], glutathione reductase [GR], and MDA), total glutathione (GSH), total ascorbate (AsA), and lipid peroxidation of two spinach cultivars (Clipper and Matador) sampled in different locations in Kosovo (Prizren, Ferizaj, and Obiliq). The photosynthetic pigments, chlorophyll a and b as well as carotenoids, were extracted by 80% acetone, and concentrations were calculated based on the absorbance values at 663, 645, and 480 nm. There was a significant difference in SOD, APX, and GR activities between varieties at each location. The MDA and AsA contents in Obiliq were the highest, compared to other locations. From the increase in lipid peroxidation level, it can be assumed that the degradation in pigment content was caused by the decrease in total AsA content and APX and GR enzyme ...
Boron (B) is an essential micronutrient for normal growth of higher plants. On the other hand, it... more Boron (B) is an essential micronutrient for normal growth of higher plants. On the other hand, its toxicity is also a significant problem that can limit plant growth on soils of arid and semi-arid environments in agricultural regions across the world. In this study, two tomato (Lycopersicon esculentum Mill.) varieties (SC2121 and SAFARI F1) are used, and toxic effects of B treatment (3 mM) were studied. Germination was not affected, and seeds of both varieties germinated nearly to 100%. These in vitro germination experiments were accomplished in MS medium. Malondialdehyde (MDA) content, and antioxidant enzyme activites (superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR)) were investigated in root and shoot tissues of tomato seedlings. Oxidative damage increased with 3-mM B treatment in tissues of SC2121 plants compared to control, and antioxidant enzyme activities were decreased, except APX. B toxicity inhibited on...
Archives of Biological Sciences, 2017
The antimicrobial properties and antioxidant enzyme activities of field-grown and in vitro- propa... more The antimicrobial properties and antioxidant enzyme activities of field-grown and in vitro- propagated plants of Digitalis trojana Ivanina (Helen of Troy foxglove), a perennial endemic plant species of Turkey, were compared. The field work was carried out in May and July 2014, and plant samples of D. trojana were collected from Kazdagi (Turkey). Propagation of D. trojana was achieved by culturing leaf explants on MS medium supplemented with 13.3 µM 6-benzylaminopurine (BA) and 0.53 µM α-naphthaleneacetic acid (NAA). The antimicrobial activity, plant lipid peroxidation levels and antioxidant enzyme (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR)) activities were analyzed in 12- and 17-week-old in vitro -grown Digitalis plants collected in May and July from two different localities at 430 and 1173 m above sea level. Although the in vitro -propagated plants had very low antagonistic activities compared to field-grown...
Fresenius Environmental Bulletin, Mar 1, 2010
Glyphosate is a broad-spectrum herbicide that can widely be used in agricultural and non-agricult... more Glyphosate is a broad-spectrum herbicide that can widely be used in agricultural and non-agricultural fields. Glyphosate isopropylamine affects the inhibition of the biosynthesis of aromatic amino acids, and also that of some enzymes involved in the shikimic acid pathway. The aim of this research was to study the effects of different concentrations of glyphosate isopropylamine (0.5, 1, 2 and 5%) on the mitotic activity in Allium cepa L. root tip cells and the superoxide dismutase (SOD) and peroxidase (POX) activities in Allium cepa L. roots. Glyphosate isopropylamine concentrations of 0.5, 1 and 2% did not lead to a significant change in the mitotic activity compared to the control group. However, for the concentration of 5%, a steep decline was observed in 48-h treatment of the substance, in comparison to that of 24 h. Total SOD activity decreased in the 24-h treatment group of glyphosate isopropylamine compared to the control group, whereas with the concentrations of 2 and 5% no SOD activity was observed. However, the POX activity increased only with 1% concentration, with regard to the control group, whereas it did not change with the other concentrations.
Fresenius Environmental Bulletin
Glyphosate is a broad-spectrum herbicide that can widely be used in agricultural and non-agricult... more Glyphosate is a broad-spectrum herbicide that can widely be used in agricultural and non-agricultural fields. Glyphosate isopropylamine affects the inhibition of the biosynthesis of aromatic amino acids, and also that of some enzymes involved in the shikimic acid pathway. The aim of this research was to study the effects of different concentrations of glyphosate isopropylamine (0.5, 1, 2 and 5%) on the mitotic activity in Allium cepa L. root tip cells and the superoxide dismutase (SOD) and peroxidase (POX) activities in Allium cepa L. roots. Glyphosate isopropylamine concentrations of 0.5, 1 and 2% did not lead to a significant change in the mitotic activity compared to the control group. However, for the concentration of 5%, a steep decline was observed in 48-h treatment of the substance, in comparison to that of 24 h. Total SOD activity decreased in the 24-h treatment group of glyphosate isopropylamine compared to the control group, whereas with the concentrations of 2 and 5% no S...
Weed Research, 2013
Salinity and Orobanche or Phelipanche spp. infection are important crop stress factors in agricul... more Salinity and Orobanche or Phelipanche spp. infection are important crop stress factors in agricultural areas. In this study, we investigated the effect of salt stress on Phelipanche ramosa seed germination and its attachment onto Arabidopsis thaliana roots. We also evaluated the effect of both stresses on the expression of genes regulated by abiotic and biotic stresses. According to our results, high concentration of NaCl delayed P. ramosa seed germination in the presence of a strigolactone analogue (GR24). A similar pattern was observed in the presence of A. thaliana plants. Furthermore, we found that salt-treated A. thaliana seedlings were more sensitive to P. ramosa attachment compared with the untreated plants, indicating that there was a positive correlation between salt sensitivity and the ability of P. ramosa to infect A. thaliana plants. At the molecular level, a synergystic effect of both salt and P. ramosa stresses was observed on the cold-regulated (COR) gene expression profile of treated A. thaliana seedlings. Our data clarify the interaction between parasitic plants and their hosts under abiotic stress conditions.
The effects of water deficit on relative water content (RWC), on the activity superoxide dismutas... more The effects of water deficit on relative water content (RWC), on the activity superoxide dismutase (SOD) and peroxidase (POX) from leaves of two drought-resistant barley strains (Hordeum vulgare L.) varieties (TOKAK-157/37 and 56000/MISC-233) and one sensitive (ERGINEL-90) were studied. In 21 day old seedlings, drought stress was initiated by withholding water and lasted for 12 days. Activity of SOD increased by the effect of drought treatments in the leaves of drought-resistant varieties TOKAK-157/37 and 56000/MISC-233 as compared to sensitive variety ERGINEL-90. The drought treatment resulted in a 418 % and 59 % increase in SOD activity in resistant varieties at the end of the 12 th day of experimental period. However, an increase in activity of SOD was not accompanied by an increase in activity of POX in drought-resistant TOKAK-157/37 and 56000/MISC-233 except on the 6 th day of drought treatment in 56000/MISC-233. In drought-sensitive variety, ERGINEL-90, POX activity did not change throughout drought period.
Boron (B) is an essential micronutrient for normal growth of higher plants. On the other hand, it... more Boron (B) is an essential micronutrient for normal growth of higher plants. On the other hand, its toxicity is also a significant problem that can limit plant growth on soils of arid and semi-arid environments in agricultural regions across the world. In this study, two tomato (Lycopersicon esculentum Mill.) varieties (SC2121 and SAFARI F1) are used, and toxic effects of B treatment (3 mM) were studied. Germination was not affected, and seeds of both varieties germinated nearly to 100%. These in vitro germination experiments were accomplished in MS medium. Malondialdehyde (MDA) content, and antioxidant enzyme activites (superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR)) were investigated in root and shoot tissues of tomato seedlings. Oxidative damage increased with 3-mM B treatment in tissues of SC2121 plants compared to control, and antioxidant enzyme activities were decreased, except APX. B toxicity inhibited on...
Boron (B) is an essential micronutrient for normal growth of higher plants. On the other hand, it... more Boron (B) is an essential micronutrient for normal growth of higher plants. On the other hand, its toxicity is also a significant problem that can limit plant growth on soils of arid and semiarid environments in agricultural regions across the world. In this study, two tomato (Lycopersicon esculentum Mill.) varieties (SC2121 and SAFARI F1) are used, and toxic effects of B treatment (3 mM) were studied. Germination was not affected, and seeds of both varieties germinated nearly to 100%. These in vitro germination experiments were accomplished in MS medium. Malondialdehyde (MDA) content, and antioxidant enzyme activities (superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), ascorbate peroxidase (APX) and glutathione reductase (GR)) were investigated in root and shoot tissues of tomato seedlings.
Oxidative damage increased with 3 mM B treatment in tissues of SC2121 plants compared to control, and antioxidant enzyme activities were decreased, except APX. B toxicity inhibited only CAT activity in root tissues, but CAT, GR, SOD, POX and APX activities were inhibited in shoot tissues of SAFARI F1. However, B toxicity in this variety did not cause oxidative damage. Root tissue of SAFARI F1 variety, in particular, was found to be a better protection than SC2121. This might indicate that SAFARI F1 variety is based on the protection of antioxidant enzymes. However, similar protections against B toxicity were not detected in shoot tissues of both varieties.
Fresenius …, Jan 1, 2010
Glyphosate is a broadspectrum herbicide that can widely be used in agricultural and non-agricultu... more Glyphosate is a broadspectrum herbicide that can widely be used in agricultural and non-agricultural fields. Glyphosate isopropylamine affects the inhibition of the biosynthesis of aromatic amino acids, and also that of some enzymes involved in the shikimic acid pathway. The aim of this research was to study the effects of different concentrations of glyphosate isopropylamine (0.5, 1, 2 and 5%) on the mitotic activity in Allium cepa L. root tip cells and the superoxide dismutase (SOD) and peroxidase (POX) activities in Allium cepa L. roots.
Glyphosate isopropylamine concentrations of 0.5, 1 and 2% did not lead to a significant change in the mitotic activity compared to the control group. However, for the concentration of 5%, a steep decline was observed in 48-h treatment of the substance, in comparison to that of 24 h. Total SOD activity decreased in the 24-h treatment group of glyphosate isopropylamine compared to the control group, whereas with the concentrations of 2 and 5% no SOD activity was observed. However, the POX activity increased only with 1% concentration, with regard to the control group, whereas it did not change with the other concentrations.
Fresenius Environmental Bulletin, Jan 1, 2008
Orobanche spp. (broomrapes) are holoparasitic angiosperms that subsist on the roots of dicotyledo... more Orobanche spp. (broomrapes) are holoparasitic angiosperms that subsist on the roots of dicotyledonous plants. Broomrapes are the most destructive weeds since they extract water and photosynthate directly from crop plants, causing crop yield and quality to reduce significantly. The occurrence of total superoxide dismutase and total peroxidase activities during broomrape–sunflower interaction were studied on three different cultivars (cv. Pioneer 4223, cv. Sanay and cv. Isera) of Helianthus annuus. Total superoxide dismutase activities increased on day 7 post-inoculation in cv. Pioneer 4223 and cv. Isera compared with control plants, whereas a decrease during all days in cv. Sanay was observed. In the variety of Orobanche-resistant cv. Pioneer 4223, the increases in the total superoxide dismutase activities were supported by the total peroxidase activities in the first 5 days, which indicate that the detoxification of the reactive oxygen species produced during the Orobanche penetration seems to be related to the Orobanche resistance in the sunflower. An increase has been determined in the total SOD activities from the first to the seventh day, but this increase was not found parallel to that in the total POX activities in cv. Isera. This situation may indicate sensitivity for cv. Isera. Total peroxidase activities increased for the first 7 days in cv. Sanay compared with control plants. Total superoxide dismutase and total peroxidase activities were not a statistically significant change during all days in treatment plants compared with control plants in cv. Sanay. This change in SOD activities may indicate sensitivity of both cv. Isera and cv. Sanay to broomrape unless they are treated with herbicide.
Papers by Sefer Demirbas
Uluslararası tarım araştırmalarında yenilikçi yaklaşımlar dergisi, Jun 29, 2023
External applications of strigolactones affect plant growth positively owing to the potential of ... more External applications of strigolactones affect plant growth positively owing to the potential of adapting plants to the tolerance system under stress conditions. In this study, the effect of synthetic analogue strigolactone (GR24) pre-treatment to the seeds of salt-tolerant and salt-sensitive bread wheat (Triticum aestivum L.) varieties on growth parameters, antioxidant enzymes, such as superoxide dismutase (SOD), ascorbate peroxidase (APX) and glutathione reductase (GR) activity under salt stress were investigated. Salt stress has inhibited shoot development. Root development of the tolerant one was better than sensitive one under salt stress conditions. Salt application to sensitive variety caused the inhibition of APX and GR activities, and pre-treatment increased these activities. In conclusion, GR24 pre-treatment has an encouraging role in the growth of wheat plants by stimulating these antioxidant enzymes against salinity.
Mediterranean Agricultural Sciences, Aug 1, 2019
Canavar otu (Orobanche cumana Wallr.) parazit bitkisi fotosentez yeteneğinden yoksun olmasından d... more Canavar otu (Orobanche cumana Wallr.) parazit bitkisi fotosentez yeteneğinden yoksun olmasından dolayı ayçiçeği (Helianthus annuus L.) üretim alanlarında enfeksiyon seviyesine bağlı olarak ciddi verim kayıplarına neden olmaktadır. Bu çalışmada, canavar otuna dayanıklı (LG5582) ve duyarlı (Özdemirbey) ayçiçeği çeşitlerinin 2003-2016 yılları arasında Tekirdağ, Kırklareli ve Edirne illerinin ayçiçeği üretimi yapılan bazı tarlalarından toplanmış canavar otu enfeksiyonundan ne derecede etkilendikleri belirlenmiştir. Öncelikle, toplanan canavar otu tohumlarının in vitro ortamda çimlenme kabiliyetleri belirlenmiştir. Sonrasında in vivo bitki yetiştirme ortamında canavar otu fidelerinin toprak yüzeyine çıktığı gün ayçiçeği bitkilerinden örneklemeler yapılarak kök/gövde uzunluğu, kök/gövde yaş ağırlığı, kök/gövde kuru ağırlığı, spesifik yaprak alanı (SLA) ve canavar otu enfeksiyon seviyesi belirlenmiştir. Elde edilen sonuçlara göre, duyarlı ayçiçeği çeşidinde en yüksek hasarın 2016 yılında toplanan canavar otu tohumlarından kaynaklandığı, 2003 yılında toplanan tohumlarının geçen süre zarfında hala çimlenebiliyor ve duyarlı ayçiçeği çeşidinde enfeksiyon yaratabiliyor olduğu, ayçiçeği bitkilerinin gelişimleri incelendiğinde enfeksiyon seviyesinde meydana gelen artışın kök uzunluğu, gövde yaş/kuru ağırlığında artışa SLA değerinde ise azalmaya neden olduğu. Ayçiçeği fidelerinin gövde uzunluğu ve kök yaş/kuru ağırlığında meydan gelen değişimlerin ise enfeksiyon ile ilişkilendirilemeyeceğini saptanmıştır.
Tritikale is a kind of cool climate grain suggested to plant in unsuitable areas for wheat farmin... more Tritikale is a kind of cool climate grain suggested to plant in unsuitable areas for wheat farming. In this thesis, it was aimed to increase of the salt tolerance of Tatlıcak-97 and Mikham-2002 genotypes with H2O2 (0, 50, 100 μM) pre-treatment to seeds under salt stress. It was determined that the effect of H2O2 pre-treatment on triticale seeds germination period in Petri dish experiment and the role of superoxide dismutase in the triticale seedling tolerance at two leaf levels against to salt stress (0, 50, 100 mM NaCl) were determined. In pot experiment, it was determined that the alteration of SOD activity and the gene expression level of SOD1.1, SOD1.2, SOD2 and SOD3 and H2O2, TBARS and leaf relative water (RWC) content in triticale seedlings at 0, 7, and 14 days after salt stress application. In the germination experiment, it was determined that increasing of NaCl concentration inhibited root and shoot length, shoot fresh and dried weigth, however 100 μM H2O2 pre-treatment removed this inhibitory effect in both genotypes. Thys, Tatlıcak-97 genotype responded to H2O2 pretreatment better than Mikham-2002 was found. According to the results of both Petri dish and pot experiment, Tatlıcak-97 genotype was more tolerant to salt stress than Mikham-2002 genotype.
Turkish Journal of Botany, Jan 11, 2019
Introduction Sunflower (Helianthus annuus L.) is one of the most significant oilseed crops in Eur... more Introduction Sunflower (Helianthus annuus L.) is one of the most significant oilseed crops in Europe, mainly grown for its edible oil and confectionery uses. Turkey takes part in the second group of sunflower producer countries (totally 27%) with China,
Kahramanmaraş Sütçü İmam Üniversitesi tarım ve doğa dergisi, Oct 31, 2022
Bu çalışmada, iki farklı lavanta bitkisinden (Lavandula latifolia (Portekiz lavantası) ve L. x in... more Bu çalışmada, iki farklı lavanta bitkisinden (Lavandula latifolia (Portekiz lavantası) ve L. x intermedia cv. Süper A) erken dönemde alınan çeliklerde in vitro ve in vivo koşullarda köklendirme çalışmaları yapılmıştır. Bitkilerden alınan çelikler ile iki farklı in vivo [Perlit (P), İndol Bütirik Asit (IBA) +Perlit (IBAP)] ve üç farklı in vitro [(Bacto Agar (B), IBA+Bacto Agar (IBAB), Hoagland+IBA+Bacto Agar (HIBAB)] olmak üzere toplamda beş farklı köklendirme denemesi kurulmuştur. Köklenmeye alınan çeliklerde 15 gün sonra uygulamalar arasında istatistiksel olarak anlamlı bir fark olduğu, en yüksek köklenme oranının IBAB uygulamasından (%89.58) elde edildiği gözlenirken; P, B ve IBAP uygulamalarında herhangi bir köklenme görülmediği saptanmıştır. Türler arasında kıyaslama yapıldığında, Portekiz lavantasının Süper A çeşidine göre daha hızlı ve daha yüksek köklenme oranına sahip olduğu belirlenmiştir. Çeliklerde yapılan uygulama sonrası 30. günde en yüksek köklenme oranının 15. günde olduğu gibi IBAB uygulamasında (%94.31), en düşük köklenme oranının ise B uygulamasında (%12.08) gözlenmiştir. Köklenme olan fideler saksıya alınarak önce nem kontrollü seraya, Nisan ayında da sağlıklı fideler koleksiyon bahçesine şaşırtılmıştır. Elde edilen sonuçlara göre, in vitro ortamda yapılan köklendirme çalışmalarında IBA kullanımının mevsimsel olgunluk beklemeden erken dönem lavanta çeliklerinde köklenmeyi hızlandırdığı saptanmıştır.
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Articles by Sefer Demirbas
Oxidative damage increased with 3 mM B treatment in tissues of SC2121 plants compared to control, and antioxidant enzyme activities were decreased, except APX. B toxicity inhibited only CAT activity in root tissues, but CAT, GR, SOD, POX and APX activities were inhibited in shoot tissues of SAFARI F1. However, B toxicity in this variety did not cause oxidative damage. Root tissue of SAFARI F1 variety, in particular, was found to be a better protection than SC2121. This might indicate that SAFARI F1 variety is based on the protection of antioxidant enzymes. However, similar protections against B toxicity were not detected in shoot tissues of both varieties.
Glyphosate isopropylamine concentrations of 0.5, 1 and 2% did not lead to a significant change in the mitotic activity compared to the control group. However, for the concentration of 5%, a steep decline was observed in 48-h treatment of the substance, in comparison to that of 24 h. Total SOD activity decreased in the 24-h treatment group of glyphosate isopropylamine compared to the control group, whereas with the concentrations of 2 and 5% no SOD activity was observed. However, the POX activity increased only with 1% concentration, with regard to the control group, whereas it did not change with the other concentrations.
Papers by Sefer Demirbas
Oxidative damage increased with 3 mM B treatment in tissues of SC2121 plants compared to control, and antioxidant enzyme activities were decreased, except APX. B toxicity inhibited only CAT activity in root tissues, but CAT, GR, SOD, POX and APX activities were inhibited in shoot tissues of SAFARI F1. However, B toxicity in this variety did not cause oxidative damage. Root tissue of SAFARI F1 variety, in particular, was found to be a better protection than SC2121. This might indicate that SAFARI F1 variety is based on the protection of antioxidant enzymes. However, similar protections against B toxicity were not detected in shoot tissues of both varieties.
Glyphosate isopropylamine concentrations of 0.5, 1 and 2% did not lead to a significant change in the mitotic activity compared to the control group. However, for the concentration of 5%, a steep decline was observed in 48-h treatment of the substance, in comparison to that of 24 h. Total SOD activity decreased in the 24-h treatment group of glyphosate isopropylamine compared to the control group, whereas with the concentrations of 2 and 5% no SOD activity was observed. However, the POX activity increased only with 1% concentration, with regard to the control group, whereas it did not change with the other concentrations.