Browsing by Author "Ucar, Sumeyra"

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Ameliorative Effects of Strigolactone on Tolerance to Lead Stress on Lettuce (Lactuca Sativa L.) Plants
(Nature Portfolio, 2025) Ucar, Sumeyra; Yuce, Merve; Yigider, Esma; Aydin, Murat; Turan, Metin; Ekinci, Melek; Yildirim, Ertan
Soil contamination by heavy metals, particularly lead (Pb), which is considered the second most toxic metal, poses serious risks to plants and humans due to its accumulation from various anthropogenic activities. Strigolactones (SLs) are a novel class of terpenoid lactones that play a vital role in regulating plant growth and development, particularly under stress conditions. This study aimed to investigate the impact of exogenous SL applications on plant growth and various physiological, biochemical, and molecular parameters in lettuce subjected to Pb stress. Pb stress harmed plant growth, whereas SL treatments improved growth parameters under both control and Pb stress conditions. While Pb stress increased the electrical conductivity (EC), malondialdehyde (MDA) and hydrogen peroxide (H2O2) content, SL applications caused a decrease in these parameters. Pb stress negatively affected chlorophyll content, whereas SL applications reduced negative effect. Pb caused an increase in superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) ascorbate peroxidase (APX), glutathione reductase (GR), glutathione s-transferase (GST) activities and Glucose-6-Phosphate Dehydrogenase (G6PD), 6-Phosphogluconate Dehydrogenase (6GPD). SL treatments significantly increased the activity of antioxidant enzymes in both control and Pb stress conditions. However, Pb stressed plants had lower nitrate reductase activity (NRA) than the control plants while SL treatments increased NRA compared to the non-treatments. Pb stress significantly reduced the uptake of essential nutrients in lettuce seedlings, whereas exogenous SL applications improved nutrient accumulation, particularly under Pb-stressed conditions. Additionally, mRNA expression profiles of nine stress-related genes in different tissues of lettuce were determined. Only Pb stress significantly decreased the expression of genes, particularly LsCCD8 and LsD14, in both tissues. The combined Pb and SL treatment significantly increased the expression of LsMAX2 in both tissues. These results suggest that exogenous SL applications can be an effective strategy to mitigate Pb-induced stress in lettuce by enhancing plant tolerance at physiological, biochemical, and molecular levels.
Chitosan Mitigated the Adverse Effect of Cd by Regulating Antioxidant Activities, Hormones, and Organic Acids Contents in Pepper ( Capsicum Annum L.)
(Cell Press, 2024) Ekinci, Melek; Shams, Mostafakamal; Turan, Metin; Ucar, Sumeyra; Yaprak, Esra; Yuksel, Esra Arslan; Yildirim, Ertan
Chitosan (CTS) is one of the natural healers' alternatives to chemical products within the scope of good agricultural practices. It can be used in the improvement of agriculture (prevention of toxic metal uptake by plants) due to its chelating feature of metal ions. This study aims to investigate the effectiveness of chitosan in eliminating the negative effects of cadmium (Cd) stress on pepper (Capsicum annum L.). The results showed that Cd stress significantly decreased plant growth, chlorophyll content, and leaf water relative content, followed by an increase in proline, antioxidant enzyme activities, and abscisic acid (ABA) content. According to the results, Cd treatment (200 mg kg-1) significantly increased the aspartate, glutamate, asparagine, histidine, and phenylalanine content, while it significantly decreased the content of endogenous hormones such as gibberellic acid (GA), indole-3-acetic acid (IAA), and salicylic acid (SA). However, CTS application decreased the uptake of Cd and caused a decrease in hydrogen peroxide (H2O2), abscisic acid (ABA), and melondialdehyde (MDA) content, as well as an increase in plant performance, and GA, IAA, and SA content in the plants grown under Cd pollution compared to the ones treated with Cd and without CTS. This study suggests that CTS application helps pepper seedlings tolerate Cd stress through a decrease in Cd uptake, and an increase in amino acids and hormone content.
Effects of Epigenetic Inhibitors on Somatic Embryogenesis in Wheat (Triticum Aestivum L.)
(Springer International Publishing AG, 2025) Ucar, Sumeyra; Aydin, Murat
Wheat (Triticum aestivum L.) is a global staple cereal known for its nutritional value and economic significance. Somatic embryogenesis (SE) is a powerful biotechnological tool for plant genetic improvement, driven by intricate epigenetic mechanisms as well as controlled by key genes such as Wuschel-related HOMEOBOX (WOX4), Leafy cotyledon (LEC1), Baby Boom 1 (BBM1), and Somatic embryogenesis receptor kinase (TaSERK). This study investigates the impact of different concentrations (0.1, 0.5, 1, and 2 mu M) of Trichostatin A (TSA) and 5-Azacytidine (5-Azac), recognized epigenetic inhibitors, on mature embryos of K & imath;r & imath;k bread wheat variety cultured in a callus formation medium. In vitro parameters including Callus formation frequency (CFF) (mg), callus fresh weight (CFW) (%), embryogenic callus formation frequency (ECFF) (%), embryogenic callus frequency (RECF) (%), and regeneration efficiency (RE) (number) as well as expression levels of WOX4, LEC1, BBM1, and TaSERK genes, were evaluated at 14, 28, and 42 days after initiation of tissue culture (DAI). The results show that TSA and 5-Azac treatments had a considerable influence on the in vitro parameters tested. Furthermore, these compounds had a significant effect on the mRNA expression levels of the WOX4, LEC1, BBM1, and TaSERK genes, which are important in SE. Specifically, LEC1 expression peaked at 42 DAI across all treatments, while WOX4 and BBM1 peaked at 14 DAI. TaSERK expression decreased by 42 DAI, with variations depending on treatment at previous time points. As a result of this study, 0.5 mu M TSA and 5 mu M 5-Azac treatments resulted in optimal plant regeneration, emphasizing the importance of epigenetic regulators in promoting somatic embryogenesis via endosperm-supported mature embryo in wheat. This study suggests addressing epigenetic systems to improve SE protocols and inform wheat genetic engineering and breeding initiatives for sustainable agriculture and food security.
Epigenetic Evaluation of Melatonin Application in Bean (Phaseolus Vulgaris L.) Genotypes under Drought and Salt Stress Conditions
(Springer, 2025) Aydinyurt, Recep; Yagci, Semra; Yaprak, Esra; Kasapoglu, Ayse Guel; Muslu, Selman; Ucar, Sumeyra; Aydin, Murat
Phaseolus vulgaris L. is an important legume used in human nutrition because it contains high protein, low fat, and high levels of vitamins and minerals. Plants are exposed to various biotic and abiotic stresses throughout their lives and have developed various resistance mechanisms. Melatonin, an animal hormone, plays a vital role in processing various metabolic processes and plant stress defense mechanisms in plants. It also supports plant growth and photosynthetic activity and regulates circadian rhythms, flowering, stress resistance, and phytohormone-mediated signal transduction pathways. This study aimed to determine the effect of melatonin applied exogenously to Serra and Elkoca 05 genotypes under drought and salt stress on biochemical and epigenetic changes in root and leaf tissues. Seeds germinated for 7 days and were then grown in Hoagland solution containers until the 5-leaf stage. Melatonin was applied to foliar by spraying at 0 and 200 mu M doses. After 24 h, they were placed in Hoagland solution containing different doses of NaCl (0 and 150 mM) and PEG6000 (0 and 20%). In the research, biochemical MDA and H2O2, antioxidant enzyme activity (SOD, POD, and CAT), and DNA methylation changes (CRED-iPBS) were detected. As a result of the research, the stresses applied on both genotypes caused an increase in the amounts of MDA and H2O2; it was determined that melatonin applied during salt stress caused a decrease in these parameters. SOD, POD, and CAT antioxidant activities of genotypes varied according to applications. On the other hand, according to DNA methylation results, stress conditions and melatonin application caused changes in DNA methylation and polymorphism rates. In summary, our research indicates that the application of melatonin proves to be a successful approach for enhancing the resilience of bean plants against both salt and drought stress.
Genome-Wide Analysis of Mir172-Mediated Response to Heavy Metal Stress in Chickpea (Cicer Arietinum L.): Physiological, Biochemical, and Molecular Insights
(BMC, 2024) Ucar, Sumeyra; Yaprak, Esra; Yigider, Esma; Kasapoglu, Ayse Gul; Oner, Burak Muhammed; Ilhan, Emre; Aydin, Murat
BackgroundChickpea (Cicer arietinum L.), a critical diploid legume in the Fabaceae family, is a rich source of protein, vitamins, and minerals. However, heavy metal toxicity severely affects its growth, yield, and quality. MicroRNAs (miRNAs) play a crucial role in regulating plant responses to both abiotic and biotic stress, including heavy metal exposure, by suppressing the expression of target genes. Plants respond to heavy metal stress through miRNA-mediated regulatory mechanisms at multiple physiological, biochemical, and molecular levels. Although the Fabaceae family is well represented in miRNA studies, chickpeas have been notably underrepresented. This study aimed to investigate the effects of heavy metal-induced stress, particularly from 100 mu M concentrations of cadmium (Cd), chromium (Cr), nickel (Ni), lead (Pb), and 30 mu M arsenic (As), on two chickpea varieties: ILC 482 (sensitive) and Azkan (tolerant). The assessment focused on physiological, biochemical, and molecular parameters. Furthermore, a systematic characterization of the miR172 gene family in the chickpea genome was conducted to better understand the plant's molecular response to heavy metal stress.ResultsVariance analysis indicated significant effects of genotype (G), treatment (T), and genotype-by-treatment (GxT) interactions on plant growth, physiological, and biochemical parameters. Heavy metal stress negatively impacted plant growth in chickpea genotypes ILC 482 and Azkan. A reduction in chlorophyll content and relative leaf water content was observed, along with increased cell membrane damage. In ILC 482, the highest hydrogen peroxide (H2O2) levels in shoot tissue were recorded under As, Cd, and Ni treatments, while in Azkan, peak levels were observed with Pb treatment. Malondialdehyde (MDA) levels in root tissue were highest in ILC 482 under Cd and Ni exposure and in Azkan under As, Cr, and Cd treatments. Antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX), were significantly elevated under heavy metal stress in both genotypes. Gene expression analysis revealed upregulation of essential antioxidant enzyme genes, such as SOD, CAT, and APX, with APX showing notable increases in both shoot and root tissues compared to the control. Additionally, seven miR172 genes (miR172a, miR172b, miR172c, miR172d, miR172e, miR172f, and miR172g) were identified in the chickpea genome, distributed across five chromosomes. All genes exhibited conserved hairpin structures essential for miRNA functionality. Phylogenetic analysis grouped these miR172 genes into three clades, suggesting strong evolutionary conservation with other plant species. The expression analysis of miR172 and its target genes under heavy metal stress showed varied expression patterns, indicating their role in enhancing heavy metal tolerance in chickpea.ConclusionsHeavy metal stress significantly impaired plant growth and physiological and biochemical parameters in chickpea genotypes, except for cell membrane damage. The findings underscore the critical role of miR172 and its target genes in modulating chickpea's response to heavy metal stress. These insights provide a foundational understanding for developing stress-tolerant chickpea varieties through miRNA-based genetic engineering approaches.
Identification and Characterization of Common Bean Ofp Gene Family Under Environmental Stresses
(Springer, 2025) Ucar, Sumeyra; Muslu, Selman; Gunes, Ebru; Kasapoglu, Ayse Gul; Aygoren, Ahmed Sidar; Yaprak, Esra; Yildirim, Ertan
The OVATE FAMILY PROTEIN (OFP) is a remarkable class of plant-specific transcription factors essential for plant growth and development. Common bean (Phaseolus vulgaris L.), the most commonly cultivated legume, was the focus of this study to evaluate the expression of OVATE genes in response to salt and drought stress, along with a genome-wide analysis of the OVATE gene family using bioinformatics tools. The study also involves comprehensive bioinformatics analyses to identify the 22 members of the Pvul-OFP gene family's conserved domains, chromosomal locations, evolutionary relationships, genetic structures, and expression patterns. Additionally, the expression levels of OFP genes in plants treated with melatonin, which has an antioxidant effect against salt and drought stress, were examined using qRT-PCR. Phylogenetic analysis revealed that Pvul-OFP genes are similar to OFP gene families found in Arabidopsis thaliana and Glycine max. Moreover, segmental duplication was detected between Pvul-OFP gene pairs. In addition, while the Pvul-OFP-2 gene had the highest expression level under salt stress, the highest expression level was determined in the Pvul-OFP-22 gene under drought stress. Moreover, it was determined that the expression levels of Pvul-OFP-7 and Pvul-OFP-20 genes did not change in both stress groups compared to the control group. The qRT-PCR results showed significant changes in the expression levels of OFP genes across different varieties and in shoot tissue. This comprehensive analysis will aid future studies associated with the functional validation of OFP genes and contribute to developing cultivars resistant to stress conditions.
Micropropagation and Genetic Fidelity of Rheum Ribes L.: A Threatened and Endemic Medicinal Herb from the Turkish Eastern Anatolia Region
(Springer, 2025) Aldaif, Muhammed; Ucar, Sumeyra; Yigider, Esma; Aydin, Murat; Kasapoglu, Ayse Gul; Ilhan, Emre
Rheum ribes L., an endemic medicinal herb of Eastern Anatolia, faces serious conservation concerns due to habitat degradation, seed dormancy, and overharvesting. To overcome these challenges, a robust and reproducible in vitro regeneration system was developed using embryo axis, hypocotyl, and cotyledon explants via direct and indirect organogenesis as well as somatic embryogenesis. The highest germination rate (88.8%) and shortest germination time were obtained using 1/2 MS medium supplemented with 1.75 mg/L GA(3) and 1.0 mg/L IBA in mature embryos. The micropropagation experiments were conducted in two stages. In the first stage, embryo axis, cotyledon, and hypocotyl explants were cultured using 36 different methods that included various culture conditions and types of plant growth regulators at differing concentrations. In the second stage, calli from these explants were cultured in the most effective medium (method 30) for callus production, and the explants were subsequently cultured in eight different regeneration media based on MS medium supplemented with varying concentrations of plant growth regulators. Callus induction reached 100% under dark conditions in MS medium containing 0.5 mg/L BAP, 0.5 mg/L KIN, and 1.0 mg/L 2,4-D. Among 36 regeneration protocols, method 13 (3.0 mg/L BAP, 0.2 mg/L NAA, 1.0 mg/L GA(3)) yielded the highest plant regeneration (1.15 plantlets/explant) in embryo axis and hypocotyl explants. In the second stage, the highest indirect somatic embryogenesis (ISER) rate (55.6%) was observed in cotyledon-derived callus (C-callus). In contrast, the highest indirect organogenesis (IOR) (28.1%) was found in embryo axis-derived callus (E-callus). The maximum number of plantlets per explant (PPEN: 1.08) was achieved in MS medium containing 2.0 mg/L BAP, 2.0 mg/L KIN, and 1.0 mg/L GA(3). Genetic fidelity of 15 regeneration systems was assessed using 20 highly polymorphic SCoT primers. Similarity coefficients between regenerated plants and the mother plant ranged from 0.904 to 0.991, with the highest genetic stability observed in plantlets derived via direct somatic embryogenesis. This optimized regeneration protocol is a powerful tool for the large-scale clonal propagation and ex-situ conservation of R. ribes, enabling both genetic preservation and sustainable biotechnological utilization of this pharmacologically valuable species.
N-Acetyl Mitigates Arsenic Stress in Lettuce: Molecular, Biochemical, and Physiological Perspective
(Elsevier France-Éditions Scientifiques Médicales Elsevier, 2024) Yuce, Merve; Yildirim, Ertan; Ekinci, Melek; Turan, Metin; Ilhan, Emre; Aydin, Murat; Ucar, Sumeyra
Agricultural land contaminated with heavy metals such as non-biodegradable arsenic (As) has become a serious global problem as it adversely affects agricultural productivity, food security and human health. Therefore, in this study, we investigated how the administration of N-acetyl-cysteine (NAC), regulates the physio-biochemical and gene expression level to reduce As toxicity in lettuce. According to our results, different NAC levels (125, 250 and 500 mu M) significantly alleviated the growth inhibition and toxicity induced by As stress (20 mg/L). Shoot fresh weight, root fresh weight, shoot dry weight and root dry weight (33.05%, 55.34%, 17.97% and 46.20%, respectively) were decreased in plants grown in As-contaminated soils compared to lettuce plants grown in soils without the addition of As. However, NAC applications together with As stress increased these growth parameters. While the highest increase in shoot fresh and dry weight (58.31% and 37.85%, respectively) was observed in 250 mu M NAC application, the highest increase in root fresh and dry weight (75.97% and 63.07%, respectively) was observed in 125 mu M NAC application in plants grown in As-polluted soils. NAC application decreased the amount of ROS, MDA and H2O2 that increased with As stress, and decreased oxidative damage by regulating hormone levels, antioxidant and enzymes involved in nitrogen metabolism. According to gene expression profiles, LsHIPP28 and LsABC3 genes have shown important roles in reducing As toxicity in leaves. This study will provide insight for future studies on how NAC applications develop resistance to As stress in lettuce.
Optimizing in Vitro Regeneration of Wheat Via Somatic Embryogenesis Using Endosperm-Supported Mature Embryos
(Tech Science Press, 2025) Ucar, Sumeyra; Aldaif, Muhammed; Yaprak, Esra; Yigider, Esma; Aydin, Murat; Ilhan, Emre; Yildirim, Ertan
Wheat is a crucial crop for global food security, and effective in vitro plant regeneration techniques are considered a precondition for genetic engineering in wheat breeding programs. A practical approach for in vitro regeneration of the K & imath;rik bread wheat cultivar via somatic embryogenesis was investigated using endospermsupported mature embryos. Callus cultures were initiated from mature embryos supported by endosperm, cultured on phytagel-based Murashige and Skoog (MS) basal medium containing dicamba (12 mg/L) and indole-3-acetic acid (IAA) (0.5 mg/L) under dark conditions. This research was designed to examine the impact of putrescine (Put) (0.0 and 1.0 mM) on inducing embryonic callus and the effects of thidiazuron (TDZ) (0.0, 0.1, 0.2, 0.3, 0.4, and 0.5 mg/L) on wheat regeneration. Adding 1.0 mM putrescine to MS medium significantly increased (p < 0.01) embryogenic callus formation, resulting in a complete (100%) induction rate. Moreover, the highest number of regenerated plants per explant (5.8) was obtained through the synergistic interaction between 1.0 mM putrescine and 0.5 mg/L TDZ. To assess the genetic homogeneity of regenerated plants, 10 different inter-simple sequence repeat (ISSR) primers were utilized, revealing a high level of genetic stability. The results of all the applications of a particular plant tissue culture technique showed a level of somaclonal variation within acceptable limits, indicating that the genetic diversity of the plant populations was protected without compromising the desired traits. These improvements offer a promising tool for wheat biotechnology, especially for genetic transformation.
Strigolactone Mitigates Nickel Toxicity by Regulating Nutrient Uptake, Antioxidant Defense, Vitamins and Phytohormones Biosynthesis in Pepper Seedlings
(Elsevier, 2026) Yildirim, Ertan; Yuce, Merve; Yaprak, Esra; Ucar, Sumeyra; Aydin, Murat; Turan, Metin; Oztemiz, Firuze
Here, pepper plants were subjected to non-stress control, control with strigolactone (SL), Nickel (Ni)-stress and Ni+ SL conditions to investigate the morpho-physiological and biochemical alterations in plant. Excess Ni produced significant negative impacts on plant's morphology, essential nutrients, and phytohormones content as compared to control plants. However, it caused tremendous increment of hydrogen peroxide (H2O2), and malondialdehyde (MDA) and the effects were further triggered by increasing concentration. Consistently, Ni induced the activity of enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) compared to control plants. It also showed downregulation of photosystem II (PSII)-related CaPsb2, aquaporin-related CaPIP1-1 and CaPIP1-2, and dehydrin-related CaDHN3 transcripts. Exogenous SL improved plant's phenotypes in control plants and greatly repaired the morphology of Ni-stressed plants. Although, sucrose accumulation was greatly enhanced by SL in Ni-stressed plants, proline content was only heightened under 500 mu M Ni. SL showed tremendous enhancement of nutrients and phytohormones in control plant and caused significant restoration of those in Ni-stressed plant. However, SL significantly reduced reactive oxygen species (ROS) in the Ni-stressed plants. This reduction correlated with elevated levels of both non-enzymatic and enzymatic antioxidants, despite the decline observed in CAT activity under extreme Ni-stressed condition. SL also showed modulation of CaPsbD transcript under Ni stress. Taken together, SL (20 mu M) produced the best results in improving most of parameters studied here, as evidenced by our multivariate analysis. The findings claim the crucial role of exogenous SL in growth and mitigation of Ni-toxicity in pepper.
Unraveling the Role of Chrysin in Mitigating Cadmium Toxicity in Pepper by Improving Antioxidant Defense, Phytohormone Biosynthesis and Photosystem II and Aquaporins Related Transcripts☆
(Elsevier Sci Ltd, 2025) Yuce, Merve; Ucar, Sumeyra; Yildiz, Mehmet; Aydin, Murat; Turan, Metin; Ghosh, Totan Kumar; Yildirim, Ertan
Cadmium (Cd) is the most dangerous and prevalent one which has tremendous impacts on global food security. Although chrysin (Chr) has been extensively studied in Cd stressed animal system, the role of this valuable flavonoid in plants is yet to be clarified. Therefore, this study was designed to determine the effects of different doses of Chr (0, 50, 150 and 300 mu M) on some physiological, biochemical and gene expression in pepper grown under Cd stress (0 and 50 mM Cd). Cd stress significantly arrested relative water, proline, essential nutrients and phytohormones content when compared to non-stressed plants. However, Cd stress caused significant enhancement of hydrogen peroxide (H2O2), melondialdehyde (MDA), and tissue electrolyte leakage (EL) and reduction of enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD), and expression of photosystem II (PSII) and aquaporin (AQPs) related transcripts compared to non-stressed plants. Compared to Cd stress, Chr positively regulated the formation of H2O2, MDA and %EL, antioxidant enzyme activity, as well as accelerated the synthesis of indole-3-acetic acid (IAA), gibberellic acid (GA) and cytokinins (CK) and reduced the level of abscisic acid (ABA), which was significantly increased by Cd stress. In addition, Chr demonstrated enhanced expression of CaPsbB, CaPsbD, CaPsb1 and CaPsb2, CaPIP1-2 and CaTIP5-1 in both root and shoots and when compared to Cd stressed plants. The findings obtained at the end of the study show that Chr is very important for alleviation of Cd toxicity in pepper plants.