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Öğe Abiotic stress of ZnO-PEG, ZnO-PVP, CuO-PEG and CuO-PVP nanoparticles enhance growth, sweetener compounds and antioxidant activities in shoots of Stevia rebaudiana Bertoni(Institution of Engineering and Technology, 2017) Javed, Rabia; Zia, Muhammad; Yücesan, Buhara; Gürel, EkremNanoparticles are known to play remarkable role as abiotic stress elicitors in plants. This study reports the comparative analysis of effects produced by capped [zinc oxide (ZnO)-polyethylene glycol (PEG), ZnO-polyvinyl pyrrolidone (PVP), copper oxide (CuO)-PEG, CuO-PVP] and uncapped (ZnO and CuO) nanoparticles on the medicinal plant, Stevia rebaudiana raised in vitro for the production of commercially important sweetener compounds. In context of shoot organogenesis, ZnO-PEG, ZnO-PVP, CuO-PEG, CuO-PVP were employed to the growth medium that resulted in increased growth parameters, and larger content of steviol glycosides as compared to the shoots raised in medium containing ZnO and CuO, revealed by high-performance liquid chromatography. In the meanwhile, non-enzymatic antioxidant activities including total phenolic content, total flavonoid content, total antioxidant capacity, total reducing power and 2,2-diphenyl-1-picryl hydrazyl-free radical scavenging activity were calculated and showed comparatively greater amounts in shoots grown in medium containing capped ZnO or CuO nanoparticles. Furthermore, the ZnO and its derivatives revealed to be more reactive at 1 mg/l of concentration. Whereas, the CuO and its derivatives produced greater response on Stevia at 10 mg/l concentration of nanoparticles. This study paves the way for more such studies encompassing capped and uncapped nanoparticles and their ultimate effect on in-vitro grown plant tissues for the production of active metabolites on industrial scale. © The Institution of Engineering and Technology 2017.Öğe Adventitious shoot regeneration from stem internode explants of Verbena Officinalis L., a medicinal plant(2010) Türker, Arzu Uçar; Yücesan, Buhara; Gürel, EkremVerbena officinalis L. (vervain) is a medicinal plant that shows several biological activities, including antimicrobial, antiinflammatory, analgesic, neuroprotective, hypnotic/sedative, gastroprotective, hepatoprotective, anticancer, cicatrizant, and antioxidant. This report describes an efficient plant regeneration system for V. officinalis via adventitious shoot development from stem internode and petiole explants. Stem internode explants were more effective than petiole explants in terms of both the number of shoots per explant and the percentages of explants forming shoots. Increasing benzyladenine (BA) concentrations steadily increased shoot formation up to 13.32 μM, but 22.22 μM BA caused a sharp decrease. The highest number of shoots (17.1 shoots per explant at 100% frequency) was obtained when 13.32 μM BA was combined with 5.71 μM indole-3-acetic acid (IAA). Rooting of the regenerated shoots was readily achieved when multiple shoots were singled out and cultured on medium containing varying concentrations of different auxins [IAA, indole-3-butyric acid (IBA), 2,4-dichlorophenoxyacetic acid (2,4-D), or naphthalene acetic acid (NAA)]. IBA was more effective in terms of the number of roots developed, producing a mean of 7.1 roots per shoot at 4.92 μM, whereas IAA was more effective for the frequency of shoots developing roots: 100% of the shoots rooted at 5.71 μM IAA. More than 90% of the regenerants survived through the hardening off process, when they were transferred to foam cups and kept under growth room conditions for 2 weeks before finally being moved to room conditions at low humidity. Approximately 3 months after the transfer to room conditions, the flowering of the regenerated plants could be observed.Öğe Analysis of metabolic variations throughout growth and development of adventitious roots in Silybum marianum L. (Milk thistle), a medicinal plant(Springer, 2015) Khan, Mubarak Ali; Abbasi, Bilal Haider; Shah, Naseer Ali; Yücesan, Buhara; Ali, HumaSilybum marianum L. is a medicinal plant used in the treatment for jaundice and liver diseases. In this study, an adventitious root culture was developed for the production of health promoting phytochemicals. Adventitious roots were induced from nodal explants on solid Murashige and Skoog medium supplemented with 1.0 mg l(-1) of alpha-Naphthalene acetic acid. Growth kinetics of the roots was investigated every week, for 8 weeks of culture period. Highest fresh biomass formation (153 mg l(-1)) was observed in 6-week old cultures. Adventitious roots were harvested from different growth stages as control (CTR), lag phase (LAG), logarithmic phase (LOG) or stationary phase (STN). Metabolite profiling of the samples was investigated using electro spray ionization time of flight mass spectrometry. Significant phenylpropanoids such as cinnamic acid and di-hydro kaempferol were predominantly found in LOG phase, whereas the highest amount of malonic acid was detected in STN as compared to other growth phases. More sucrose content was detected in CTR, while the tryptophan content was higher in LOG phase. Among the vital fatty acids, prostaglandin A1 and phenyl acetic acid were at highest levels in STN phase. However, more brassicasterols were observed in LAG phase than other growth phases. Punicic acid and lignan pinoresinol were detected abundantly in the LOG phase. Biochemical characterization revealed significant correlations between silymarin content and DPPH as well as TPC and TFC in the growth curve. Interestingly, among all growth stages there was no correlation of PAL activity with TFC and silymarin content.Öğe Cardenolide estimation in callus-mediated regenerants of Digitalis lamarckii Ivanina (dwarf foxglove)(Springer, 2014) Yücesan, Buhara; Müller-Uri, Frieder; Kreis, Wolfgang; Gürel, EkremDigitalis cardenolides can regulate heart rhythms and are effective agents in cancer chemotherapy, in particular, for treating prostate and breast cancer. In this study, an optimized and efficient plant tissue culture protocol was established using callus cultures of Digitalis lamarckii Ivanina, commonly known as dwarf foxglove. Lamina explants developed callus when cultured on Linsmaier and Skoog (LS) medium containing different concentrations of 6-benzyladenine (BA; 4.4, 13.3, or 22.2 mu M) and alpha-naphthalene acetic acid (NAA; 2.7, 5.4, or 10.8 mu M). The highest incidence of callus formation (100%) was achieved on LS medium containing 13.3 mu M BA and 10.8 mu M NAA. Indirect shoot regeneration was achieved when the callus explants were cultured on LS medium supplemented with varying concentrations of BA (0.4, 1.1, or 2.2 mu M) and/or gibberellic acid (0.7 or 1.4 mu M) for 8 wk. Following the rooting of shoots on LS medium supplemented with either indole-3-acetic acid (ranging from 1.4 to 5.7 mu M) or NAA (1.3 to 5.2 mu M), lamina and petiole tissues of the 4-mo-old regenerated plants were compared for their cardenolide contents. Lamina extracts showed nearly three times higher cardenolide accumulation than petiole extracts. Of the cardenolides analyzed by reverse-phase high-performance liquid chromatography, neo-odorobioside G and glucogitoroside were abundant in lamina extracts (170.3 and 143.9 mg/kg dry weight, respectively). The regeneration protocol described in this study can be used for the in vitro production of certain cardenolides from D. lamarckii.Öğe Cardiotonic glycoside determination in in vitro and ex vitro samples of Digitalis lamarckii Ivan, an endemic species to Anatolia(Georg Thieme Verlag Kg, 2010) Yücesan, Buhara; Gürel, EkremDigitalis lamarckii Ivan is an endemic species to Turkey. Digitalis species are medicinally and economically important as they contain cardiac glycosides that strengthen diffusion and regulate the heart rhythm [1]. Moreover, preliminary studies have revealed that digoxin and digitoxin are also effective agents in several cancer treatments [2]. In this study cardenolide patterns in in vitro and ex vitro (from natural populations) samples of D. lamarckii were studied. In in vitro samples, digoxin was predominantly found in different tissues (lamina, petiole or whole shoot) of 12 or 18-week old regenerants. Digoxin content was, in general, lower in the 18-week old regenerants than 12-week old ones (Fig.1).Öğe Chemical and enzymatic modifications of steviol glycosides(Elsevier, 2020) Yücesan, Buhara; Altuğ, CevherSteviol glycosides are known as zero-calorie high-intensity sweetening compounds sourced from Stevia rebaudiana. The extraction, isolation, and purification of the sweetener compounds are based on either conventional techniques that use multistep processes and may contain some impurities, or enzymatic/chemical modification methods for certain steviol compounds for large-scale production that may aim to the demand of the global sweetener market. For the chemical modification of the synthesis of value-added steviol glycosides from extracted leaf samples, industrial applications of chemical methods appear to be impractical due to process yield not meeting the expectations of large-scale production, and the lack of cost-effectiveness. Conventional techniques and chemical modifications in some cases give rise to the toxic chemical reagents that are likely to cause severe problems for the food industry. Enzymatic modifications for the next-generation steviol glycoside (SG) through microbial organisms could be a key factor to obtain high-quality SGs for potential consumers. However, there remain authorization problems for these novel techniques, and each should be examined thoroughly before use. © 2020 Elsevier Inc. All rights reserved.Öğe Direct somatic embryogenesis from hypocotyl segments of Digitalis trojana Ivan and subsequent plant regeneration(Elsevier, 2012) Verma, Sandeep Kumar; Şahin, Günce; Yücesan, Buhara; Eker, İsmail; Şahbaz, Nevin; Gürel, Songül; Gürel, EkremThis study describes, for the first time, an in vitro protocol for the direct development of somatic embryos and subsequent plant regeneration from hypocotyl segments excised from 21-days-old in vitro-germinated seedlings of Digitalis trojana Ivan (Helen of troy foxglove). Two sets of experiments were carried out, the first compared different concentrations of four cytokinins: N6-benzyladenine [BAP], 6-furfurylaminopurine [kinetin], 1-phenyl-3-(1,2,3-thiadiazol-5-yl)-urea [TDZ], and 6-(4-hydroxy-3-methylbut-2-enylamino) purine [zeatin] I alone, while the second set tested TDZ or BAP combinations with IAA (indole-3-acetic acid), IBA (indole-3-butyric acid) or NAA (alpha-naphthalene acetic acid). In the first set of experiments, TDZ was found the most effective at 1.0 mg/l concentration, producing a mean of 10.7 somatic embryos per explant. In the second set, a combination of 1.0 mg/l TDZ with 0.5 mg/l IAA produced significantly more somatic embryos per explant (13.8 embryos) than with BAP (8.8 embryos). During subculture on growth regulator-free half-strength MS medium, somatic embryos gradually developed into plantlets. Regenerated plantlets were successfully transplanted and grown in a greenhouse environment. The efficient regeneration protocol reported here provides an important method of micropropagation of this plant. Furthermore, this protocol may be used for a large-scale production of cardenolides and genetic transformation of this valuable medicinal plant for its further improvement. (C) 2012 Elsevier B.V. All rights reserved.Öğe Effect of zinc oxide (ZnO) nanoparticles on physiology and steviol glycosides production in micropropagated shoots of Stevia rebaudiana Bertoni(Elsevier France-Editions Scientifiques Medicales Elsevier, 2017) Javed, Rabia; Usman, Muhammad; Yücesan, Buhara; Zia, Muhammad; Gürel, EkremThis study aims to address the effects of different concentrations (0, 0.1, 1.0, 10, 100 or 1000 mg L-1) of engineered zinc oxide (ZnO) nanoparticles (34 nm in size) on growth parameters, steviol glycosides (rebaudioside A and stevioside) production and antioxidant activities in the tissue culture grown shoots of Stevia rebaudiana Bertoni. The highest percentage of shoot formation (89.6%) at 1 mg L-1 of ZnO nanoparticles concentration suggests a positive influence of ZnO nanoparticles on S. rebaudiana growth as compared to other treatments with or without ZnO nanoparticles. Additionally, HPLC results illustrate a significant enhancement of steviol glycosides (almost doubled as compared to the control) in micro propagated shoots grown under an oxidative stress of 1 mg L-1 of ZnO nanoparticles. This finding is further affirmed by an increased 2,2-diphenyl-1-picryl hydrazyl (DPPH) scavenging activity, total antioxidant capacity, total reducing power, total flavonoid content and total phenolic content, with an ascending oxidative pressure and generation of reactive oxygen species (ROS). However, the antioxidant activities, formation of secondary metabolites and the physiological parameters showed a sudden decline after crossing a threshold of 1 mg L-1 concentration of ZnO nanoparticles and falls to a minimum at 1000 mg L-1, elucidating maximum phytotoxic effect of ZnO nanoparticles at this concentration. This is the first study evaluating both the favorable and adverse effects of ZnO nanoparticles employed to a highly valuable medicinal plant, S. rebaudiana. (C) 2016 Elsevier Masson SAS. All rights reserved.Öğe Effects of cytokinins, gibberellic acid 3, and gibberellic acid 4/7 on in vitro growth, morphological traits, and content of steviol glycosides in Stevia rebaudiana(Elsevier France-Editions Scientifiques Medicales Elsevier, 2019) Pazuki, Arman; Aflaki, Fatemeh; Yücesan, Buhara; Gürel, SongülSteviol glycosides (SGs) and gibberellic acids share a part of their biosynthesis pathways. Despite the widespread studies on the effect of gibberellic acid 3 (GA(3)), the effect of gibberellic acid 4 and 7 (GA(4/7)) on Stevia rebaudiana has never been studied. This study aimed at a comparative evaluation of different hormone effects, i.e., 1 mg L(-1)GA(4/7), 1 mg L(-1)GA(3), or 0.5 mg L(-1)kinetin and 0.5 mg L-1 6-benzylaminopurine (BAP) (KB 0.5), on in vitro propagation, growth, morphological properties, and content of SGs in leaf samples of stevia. In comparison with the control group (hormone-free), the treatments of KB 0.5 or GA(3) produced the highest biomasses and largest leaf areas. The three hormonal treatments produced a similar number of leaves, the ratio of fresh to dry weight, and leaf length. GA(4/7) treated explants produced the highest ratio of leaf area to leaf length. The effect of Gk(4/7) on shoot elongation was greater than that of the control or even GA(3). While the effect of GA(3) on rebaudioside-A (Reb-A) production was similar to that of the control (16.2 and 18.04 mg g(-1), respectively), GA(4/7) resulted in a lower amount of it (13.31 mg g(-1)). Except for GA(4/7), which induced more stevioside accumulation, the treat.ments' effects were comparable to that of the control. The ratio of stevioside to Reb-A was the highest for GA(4/7) (2.62), followed by GA(3)(1.93), and then the two others. Sum of Reb-A and stevioside content was not changed by the use of any of the treatments.Öğe Effects of exogenous auxin and auxin transport inhibitor on somatic embryogenesis and analysis of cardenolides in Digitalis lamarckii Ivan(Georg Thieme Verlag Kg, 2010) Verma, Sandeep; Yücesan, Buhara; Gürel, EkremDigitalis lamarckii (Plantaginaceae), is an endemic species of the Turkish flora. D. lamarckii are medicinally important plants as they contain cardiac glycosides that strengthen the cardiac diffusion and regulate the heart rhythm [1]. Hypocotyl sections excised from 21days old seedlings of D. lamarckii were used to test the effect of indole-3-acetic acid (IAA) on direct somatic embryogenesis. Although direct somatic embryogenesis was obtained with all IAA concentrations (0.1, 0.5 and 1mg/l) from the upper part of hypocotyl explants (Fig.1), optimum results were achieved with 1mg/l IAA. Several studies have shown that proper polar transport of auxin is a pre-requisite for normal embryogenesis beyond the globular stage [2]. The auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA) blocks morphological transitions to subsequent stages; for example, they cause the formation of enlarged globular and oblong embryos. We observed morphologically abnormal embryos developed on media supplemented with auxin polar transport inhibitors (0.1–2mg/l IAA with 1–5mg/l TIBA). TIBA disrupts somatic embryogenesis and thus specific spatial auxin distribution due to auxin movement may be important in establishing somatic embryo development in D. lamarckii. In the present investigation, contents of five cardenolides as well the total cardenolide contents of the direct somatic embryos were determined, the amount of total cardenolides being 380mg/kg. It has been reported that somatic embryos of the globular stage turned green and, concomitantly, started to produce cardiac glycosides in Digiltalis lanata [3,4].Öğe Effects of storage durations at different temperatures on various physiological parameters of einkorn seed (Triticum monucocum L.) germination(Pergamon-Elsevier Science, 2021) Kibar, Hakan; Yücesan, BuharaIn this present study, seed vigor was tested after different storage durations (0, 60, 120, 180 days; maximum 420 days) in air-conditioning cabinets set to various temperatures (4, 10, 20 degrees C) and free-temperature at room condition. After seven days for each of the storage durations, germination rate (GR), mean germination time (MGT), germination speed (GS), seed vigor index (SVI), shoot and root length (SL, RL), shoot and root dry weight (SDW, RDW), root number (RN), electrical conductivity (EC) and pH for all seed lots were recorded. The average GR at room temperature storage decreased from 86% recorded on the 60th day, to 59% by the end of the 420th day, while germination rate was still around 70% with the seeds stored at 4 degrees C. The decrease in GS was recorded after the 300th day till the end of 420 days of storage (ranging between 9.8 and 9.4 seed day(-1)). The lowest SVI was 7.9 at the beginning of storage (day 0) and increased gradually within 60 days of storage for all temperatures tested. Irrespective of storage duration, the SL and RN showed the highest overall mean of 10.7 cm and 4.8 root for the seeds stored at 4 degrees C. EC sharply decreased overall to a mean of 18.9 mu Scm(-1) g(-1) for all temperatures within the first 60 days of storage. The highest correlation (r = 0.937) was determined between GS and MGT. This study provides a new insight to the farmers for better understanding that concerns practical implications of einkorn farming as follows: storage at 4 degrees C is best way of the maintanence of highest seed vigor. For the storage duration regardless of the temperatures, it can be kept minimum 60 days, since the seed deterioration can be effective after 180 days of storage depending on storage temperature.Öğe An efficient regeneration system and steviol glycoside analysis of Stevia rebaudiana Bertoni, a source of natural high-intensity sweetener(Springer, 2016) Yücesan, Buhara; Büyükgöçmen, Refik; Mohammed, Aliyu; Sameeullah, Muhammad; Altuğ, Cevher; Gürel, Songül; Gürel, EkremStevia is a natural, zero-calorie, intensively sweet extracted from the leaves of Stevia rebaudiana. Its sweet taste derives from a group of compounds known as steviol glycosides. In this study, an efficient micropropagation protocol for S. rebaudiana was developed for possible commercial implementation using Murashige and Skoog (MS) basal medium without plant growth regulators for most of the process. Direct shoot formation was achieved after cultivation of nodal segments on MS medium with or without plant growth regulators (benzyl amino purine [BAP], kinetin [KIN]) at various concentrations (0.1, 0.5, 1.0, or 2.0 mg L-1). Although all treatments produced two shoots per explants after 3 wk of culture, high concentrations of KIN and BAP (1.0 or 2.0 mg L-1) induced more callus formation. Rooting was achieved on MS medium containing 0.25 mg L-1 indole-3-acetic acid (IAA), which produced 8.1 roots per shoot after 3 wk of cultivation. After acclimatization of the regenerants in a portable greenhouse for 3 wk, all regenerants and seed-derived seedlings were transferred to field conditions for 16 wk. Steviol glycoside contents (% leaf dry weight) did not differ between leaves collected from regenerants and seed-derived plants. Rebaudioside A content ranged from 4.7 to 5.0% (w/w), while stevioside ranged from 6.4 to 6.9% (w/w). There was no significant difference between the two sampling periods (late vegetative and flowering stages) for the plants grown in the field. In this study, a cost-effective in vitro regeneration protocol was established that enables efficient, large-scale in vitro production of S. rebaudiana for field cultivation.Öğe Elicitation of Secondary Metabolites in Callus Cultures of Stevia rebaudiana Bertoni Grown Under ZnO and CuO Nanoparticles Stress(Springer India, 2018) Javed, Rabia; Yücesan, Buhara; Zia, Muhammad; Gürel, EkremAccumulation of secondary metabolites in medicinal plants by giving abiotic/biotic stress is, nowadays, an active area of research. This study reports the inoculation of ZnO and CuO nanoparticles in Murashige and Skoog (MS) medium having plant growth regulators for the regeneration of callus from leaf explants of medicinal plant, Stevia rebaudiana. Presence of ZnO and CuO nanoparticles in different concentrations results in conferring different kinds of physiology in different regenerants. 1 and 10 mg/L have been declared the best ZnO and CuO nanoparticles concentrations regarding various physiological parameters. Steviol glycosides have not been detected in any callus treatment. Moreover, the phytochemical characteristics of S. rebaudiana under different ZnO and CuO nanoparticles concentrations have been exploited. The highest amount of total phenolic content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity has been obtained at 100 mg/L of ZnO nanoparticles, whereas TPC, TAC, TRP and DPPH free radical scavenging activity have been achieved highest at 10 mg/L concentration of CuO nanoparticles. However, the highest TRP in the context of ZnO and the highest TFC regarding CuO have been achieved at 50 and 100 mg/L, respectively. This clearly indicates that CuO nanoparticles are more toxic to Stevia callus as compared to ZnO nanoparticles, and opens avenues for future studies utilizing ZnO or CuO nanoparticles for the enhancement of commercially important secondary metabolites in different medicinal plants. © 2017, Society for Sugar Research & Promotion.Öğe Embryogenesis, plant regeneration and cardiac glycoside determination in Digitalis ferruginea subsp ferruginea L(Springer, 2014) Verma, Sandeep Kumar; Yücesan, Buhara; Şahin, Günce; Gürel, EkremThe present study reports, for the first time, an efficient in vitro plant regeneration protocol for Digitalis ferruginea subsp. ferruginea L. (rusty foxglove). We have used different concentrations of gibberellic acid (GA(3)) on Murashige and Skoog (MS) medium to assess the germination frequency of seeds. High frequency of germination was achieved on MS medium with 1.0 mg l(-1) GA(3). 6-Benzylaminopurine (BAP) combined with alpha-naphtaleneacetic acid (NAA) or 2, 4-dichlorophenoxy acetic acid (2, 4-D) in the induction MS medium induced both somatic embryogensis and shoot organogenesis. The highest percentage of callus growth (85 %) was obtained when hypocotyl explants were cultured on MS medium containing 0.5 mg l(-1) 2, 4-D plus 1.0 mg l(-1) BAP. The maximum mean number of somatic embryos (7.3 +/- A 1.3 embryos) or shoots (12.0 +/- A 1.1 shoots) per callus was obtained when medium contained 0.25 mg l(-1) NAA plus 1.0 mg l(-1) BAP or 0.5 mg l(-1) NAA plus 2.0 mg l(-1) BAP. The regenerated shoots easily rooted on MS medium. Higher amounts of lanatoside C [13.2 +/- A 0.5 mg 100 g(-1) dry weight (dw)] and digoxin (2.93 +/- A 0.31 mg 100 g(-1) dw) accumulation were obtained when shoots were obtained by indirect regeneration. We also investigated derivatives of cardenolides, i.e., digitoxigenin (730 +/- A 180 mg 100 g(-1) dw), gitoxigenin (50 +/- A 20 mg 100 g(-1) dw) and digoxigenin (490 +/- A 170 mg 100 g(-1) dw) from natural samples.Öğe Evaluation of biochemical markers during somatic embryogenesis in Silybum marianum L.(Springer Heidelberg, 2016) Abbasi, Bilal Haider; Ali, Huma; Yücesan, Buhara; Saeed, Sabahat; Rehman, KhalidIn present report effects of explants type, basal media and plant growth regulators (PGRs) were tested for induction of indirect somatic embryogenesis in medicinally important plant Silybum marianum L. Leaf, petiole and root explants were exploited in vitro on B5 (Gamborg), SH (Schenk and Hildebrandt) and MS (Murashige and Skoog) media for induction of embryogenic callus followed by somatic embryogenesis. Highest callus induction frequency (76 +/- 4.8 %) was recorded when petiole explants of in vitro derived plantlets were cultured on B5 medium supplemented with 1.5 mg l(-1) 2,4-dichlorophenoxyacetic acid (2,4_D) in combination with 1.5 mg l(-1) Thidiazuron (TDZ). Induction and multiplication of somatic embryos were observed, when the embryogenic calluses were sub-cultured on to B5 medium containing 0.5 mg l(-1) 2,4-D plus 1.5 mg l(-1) TDZ. At this PGRs treatment, 77 % of the cultures responded with 39.1 somatic embryos per callus. Furthermore, MS0 medium was indicated more reponsive for growth and maturation of somatic embryos. Analysis of biochemical markers during various growth phases in somatic embryogenesis revealed that somatic embryos exhibited highest level of total carbohydrate, starch, ascorbic acid and total free amino acids. However, higher protein levels were detected in non-embryogenic callus. Nevertheless, considerable amount of silymarin (4.1 mg g(-1) DW) was detected in somatic embryos than other growth phases. Thus, the present study concluded that biochemical and physiological changes during embryogenesis are influenced by interplay of explants type, basal media and PGRs.Öğe High-frequency plant regeneration via direct and indirect somatic embryogenesis and cardiotonic glycoside production in digitalis ferruginea(Springer, 2010) Verma, Sandeep; Yücesan, Buhara; Şahin, Günce; Gürel, Ekrem[No Abstract Available]Öğe Impact of Stevia rebaudiana Culturing in Liquid Medium: Elevation of Yield and Biomass, Mitigation of Steviol Glycosides(Giunti, 2022) Javed, Rabia; Yücesan, BuharaAn efficient micropropagation system is developed by culturing nodal segments containing the axillary shoot buds on liquid Murashige and Skoog (MS) medium. Direct shoot and root formation are highly effective in both solid and liquid MS media without any plant growth regulators (PGRs). Interestingly, a significant difference in yield is obtained between solid and liquid cultures. It is revealed that a relatively higher amount of plant biomass is obtained after culturing for 4 weeks in a liquid MS medium. However, the shoots produced on solid MS medium produce a remarkable decline in all physiological parameters. On contrary, the bioactive steviol glycosides (rebaudioside-A and stevioside) content is higher in shoots grown in solid MS on a comparative basis, which could be compensated by higher yield. After hardening off, all the regenerants are effectively grown in the field with a negligible loss (<1 %), and steviol glycosides spectra is again obtained by conducting high-performance liquid chromatography (HPLC) analysis after 10 weeks of the plantation. This method has great potential to be applied on large scale in bioreactors. © Pakistan Academy of SciencesÖğe In vitro and ex vitro propagation of Stevia rebaudiana Bertoni with high Rebaudioside-A content-A commercial scale application(Elsevier, 2016) Yücesan, Buhara; Mohammed, Aliyu; Büyükgöçmen, Refik; Altuğ, Cevher; Kavas, Özge; Gürel, EkremStevia rebaudiana Bertoni is a self-incompatible and the pollination is an entomophilous short-day plant. Rebaudioside A, as an individual steviol glycoside, is of particular interest in global sweetener market due to its most desirable flavour profile as compared to stevioside having aftertaste bitterness. In the present investigation, regenerant formation was performed for 6 weeks, in which randomly selected nodes excised from in vitro germinated seedlings were cultured on solid Murashige and Skoog medium (MS) with or without growth regulators (6-benzylaminopurine- BAP or kinetin- KIN) at various concentrations (ranging from 0.1 to 2.0 mg/L). Irrespective of the medium composition, the results showed that all treatments were effective for shoot induction, producing an average of 2 shoots per explant after three weeks of culture. Following subsequent sub-culturing on MS medium at 3-week intervals, all the shoots regenerated from the nodes were transferred to MS medium with or without indole-3-acetic acid (IAA), indole-3-butyric acid (IBA) or naphthalene acetic acid (NAA) at two different concentrations (0.25 or 0.50 mg/L) for root formation for 3 weeks. IAA was more effective for root formation, producing 7.6 roots per shoot with 100% rooting frequency. All the regenerants (similar to 13.5 cm in length) were potted and successfully acclimatized in a greenhouse for 2 weeks, and then transferred to the field for 14 weeks with a high survival rate (>99%). Similarly, seedlings (8 weeks-old) derived from seed germination in pots were also transferred to the same field in a different plot. There was no significant difference in terms of morphological, yield performance and steviol glycoside compositions between regenerants and seedlings sampled from two developmental periods (late vegetative and flowering period). It was clearly shown that clonal propagation using nodal explants was effective for superior stock plant production with high Reb-A content (11.7% w/w). (C) 2016 Elsevier B.V. All rights reserved.Öğe In vitro propagation and cardenolide profiling of Digitalis ferruginea subsp schischkinii, a medicinally important foxglove species with limited distribution in Northern Turkey(Springer, 2016) Yücesan, Buhara; Mohammed, Aliyu; Eker, İsmail; Sameeullah, Muhammad; Demir-Ordu, Öznur; Cihangir, Cansu; Şahbaz, Nevin; Kaya, Özge; Gürel, EkremCardenolides isolated from genus Digitalis are natural compounds used in treating cardiac insufficiencies. Recent investigations have also suggested the use of cardenolides in oncology. Due to the medicinal importance of the genus Digitalis, in vitro regeneration techniques would be useful for propagating the best genotypes selected from natural sources. To achieve this, Digitalis ferruginea subsp. schischkinii (Ivanina) K. Werner was collected from different locations along the Black Sea region of Turkey. In the cardenolide analysis, samples from Giresun and Trabzon showed a greater diversity than those from other locations, and thus, the Trabzon population was selected for plant tissue culture studies. In vitro regeneration was performed using cotyledonary leaves and hypocotyl segments on Murashige and Skoog (MS) medium containing various concentrations (0.5, 1.0, or 2.0 mg L-1) of 6-benzyladenine (BA), kinetin (KIN), or thidiazuron (TDZ) alone or in combination with indole-3-acetic acid (IAA) at 0.5 or 1.0 mg L-1. Among the media used for shoot regeneration, the highest frequency of shoot organogenesis was obtained from MS medium containing 2.0 mg L-1 TDZ and 0.5 mg L-1 IAA, producing 11.0 shoots per explant with 100% regeneration frequency from hypocotyl explants after 4 wk. For successful rooting, IAA was the most effective at 1.0 or 2.0 mg L-1, producing 16.3 or 17.3 roots per shoot, respectively, after 4 wk. Regenerants from several medium types were grown in a greenhouse for 6 mo, and all displayed similar cardenolide contents, i.e., the lanatoside C level was around 0.3% (w/w) while the levels of lanatosides A and B, digoxin, and digitoxin were less than 0.08% (w/w), similar to plants grown from seeds collected from Trabzon district.Öğe In vitro propagation of a medicinal plant witloof chicory (Cichorium intybus L.)(Bolu Abant İzzet Baysal Üniversitesi, 2005) Yücesan, Buhara; Gürel, EkremTıbbi bir bitki olan yabani hindibanın üretilmesinde çeşitli yaprak eksplantları kullanılmıştır. Öncelikle tohumlar sterilize edilip çimlenme için MSMO hazır besin ortamına alınmıştır. Daha sonra çimlenen bitkilerden yaprak ayası ve sapı, çeşitli hormon içeren besin ortamlarına konulmuştur. Bunlardan yaprak ayası eksplantı, 0.3 mg/l IAA`nın 0.5 mg/l KIN ile kombinasyonunu içeren ortamlarda 3 hafta gelişerek, yüksek sayıda sürgün oluşturmuştur (eksplant başına ortalama 19,65 sürgün).Deneyin ilerleyen kısımlarında KIN ve IAA'ya ek olarak NAA, BAP ve TDZ kullanılmış ve bunların sürgün oluşumu üzerideki etkisi incelenmiştir.0.3 mg/l NAA'nın 0.5 mg/l BAP veya KIN ile kombinasyonunda kallus oluşumu göze çarpmıştır. Ayrıca TDZ'nin düşük konsantrasyonlarında yüksek sayıda sürgün oluşumu gözlenmesine rağmen yaprak iyi gelişmemiştir.Köklendirme için sürgünler oksin (2,4-D, IBA, NAA veya IAA) içeren besin ortamlarına alınmıştır. Bunlardan en iyi sonuç veren 0.5 mg/l IAA içeren ortam olup (sürgün başına ortalama 4,24 kök) IAA'nın yüksek konsantrasyonlarında bu sayı düşmüş ve ayrıca sürgün ve kök gelişiminin yavaşladığı görülmüştür. Bunların dışında köklendirme için kullanılan 2,4-D veya NAA kök ve sürgün gelişimi açısından düşük sonuçlar vermiştir.İklimledirme için IAA veya IBA içeren ortamlarda gelişmiş sürgünler saksılara alınmış ve dış ortama uyum sağlama süreci başlatılmıştır. Böylece, yabani hindiba üretimi 8-10 haftada tamamlanmıştır.
