Browsing by Author "Agar, Guleray"

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Ameliorative Effects of SL on Tolerance to Salt Stress on Pepper (Capsicum Annuum L.) Plants
(Elsevier France-Éditions Scientifiques Médicales Elsevier, 2025) Yuce, Merve; Aydin, Murat; Turan, Metin; Ilhan, Emre; Ekinci, Melek; Agar, Guleray; Yildirim, Ertan
Salinity is one of the most important problems that threaten agricultural production, especially in arid and semiarid areas. Strigolactones (SLs) are important in providing tolerance to various abiotic stresses in plants. The study was carried out in a hydroponic system to determine the effects of external GR24 (were applied as a foliar spray; 0, 10, and 20 mu M) applications at different doses on plant growth and some physiological, biochemical, and gene expression in two pepper genotype (Yalova and Maras,) grown under salt stress (0 and 100 mM NaCl). Plants were harvested and measured 10 days after the NaCl treatments. At the end of the research, it was determined that salt stress negatively affected plant growth in both genotype. Still, SL applications positively affected plant development both under normal and salt stress. While salt stress increased the amount of hydrogen peroxide (H2O2) and malondialdehyde (MDA), SL application caused a decrease in these parameters. Salt stress negatively affected the amount of chlorophyll and photosynthetic properties in both genotype, whereas SL applications mitigated this negative effect. SL applications caused a significant increase in antioxidant enzyme activities under both normal and salt stress conditions. SL content, which decreased with salt stress, increased with exogenous SL application. The content of other plant nutrients except sodium (Na) and chloride (Cl) decreased significantly in pepper seedlings grown under salt stress. External SL applications increased the uptake of these nutrients, especially under salt stress. In addition, the expression levels of CIPK3, CBL2, CCD7, DMAX2, PsbA, PsbB, PsbP1, TIP1;2, TIP5;1, SOS1, SOS2 and HKT2;2 genes were investigated in this study. It was observed that the expression levels of CCD7, DMAX2, SOS1, SOS2, and HKT2;2 genes increased with salinity stress, especially in the Maras, genotype, while SL applications decreased these expression levels. In the study, it was determined that especially exogenous 20 mu M SL application could significantly reduce the negative effects of salt stress in pepper.
Antibacterial Activity and Chemical Composition of Essential Oil Obtained from Nepeta Nuda Against Phytopathogenic Bacteria
(Taylor & Francis Inc, 2013) Gormez, Arzu; Bozari, Sedat; Yanmis, Derya; Gulluce, Medine; Agar, Guleray; Sahin, Fikrettin
The increase in agricultural production can be possible with the discovery and utilization of chemical compounds for plant disease control. However, indiscriminate use of chemical compounds against microorganisms causes many negative side effects on environment and mammalian health. Therefore, we aimed to find a new natural antimicrobial product from medicinal plants against phytopathogenic bacteria. In this study, the essential oil (EO) of Nepeta nuda was isolated by the hydrodistillation method and the chemical composition of the EO was analyzed by gas chromatography-mass spectrometry (GC-MS), as its biological activity was connected to its content. Then, the antibacterial property of EO was evaluated against twenty phytopathogenic bacteria. Nepeta contains 4a,7,7a-nepetalactone (18.10%), germacrene (15.68%), elemol (14.38%), -caryophyllene (8.81%), spathulenol (6.14%) and cubenol (5.10%) as major components. In conclusion, the present study is valuable for future investigations on controlling plant pathogenic bacteria.
Characterization of Two-Component System Gene (TCS) in Melatonin-Treated Common Bean Under Salt and Drought Stress
(Springer, 2023) Kasapoglu, Ayse Gul; Ilhan, Emre; Aydin, Murat; Yigider, Esma; Inal, Behcet; Buyuk, Ilker; Agar, Guleray
The two-component system (TCS) generally consists of three elements, namely the histidine kinase (HK), response regulator (RR), and histidine phosphotransfer (HP) gene families. This study aimed to assess the expression of TCS genes in P. vulgaris leaf tissue under salt and drought stress and perform a genome-wide analysis of TCS gene family members using bioinformatics methods. This study identified 67 PvTCS genes, including 10 PvHP, 38 PvRR, and 19 PvHK, in the bean genome. PvHK2 had the maximum number of amino acids with 1261, whilst PvHP8 had the lowest number with 87. In addition, their theoretical isoelectric points were between 4.56 (PvHP8) and 9.15 (PvPRR10). The majority of PvTCS genes are unstable. Phylogenetic analysis of TCS genes in A. thaliana, G. max, and bean found that PvTCS genes had close phylogenetic relationships with the genes of other plants. Segmental and tandem duplicate gene pairs were detected among the TCS genes and TCS genes have been subjected to purifying selection pressure in the evolutionary process. Furthermore, the TCS gene family, which has an important role in abiotic stress and hormonal responses in plants, was characterized for the first time in beans, and its expression of TCS genes in bean leaves under salt and drought stress was established using RNAseq and qRT-PCR analyses. The findings of this study will aid future functional and genomic studies by providing essential information about the members of the TCS gene family in beans.
Chemical Composition and Antibacterial Activity of Essential Oils of Two Species of Lamiaceae Against Phytopathogenic Bacteria
(Polskie Towarzystwo Mikrobiologow-Polish Society of Microbiologists, 2015) Gormez, Arzu; Bozari, Sedat; Yanmis, Derya; Gulluce, Medine; Sahin, Fikrettin; Agar, Guleray
In this study, we aimed to determine chemical composition and antibacterial activities of Satureja hortensis and Calamintha nepeta against to 20 phytopathogenic bacteria causing serious crop loss. The essential oils of S. hortensis and C. nepeta were isolated by the hydrodistillation method and the chemical composition of the essential oils were analyzed by GC-MS. The antibacterial properties of the essential oils were evaluated against 20 phytopathogenic bacteria through Disc diffusion assay and micro dilution assay. The results revealed that the essential oils of S. hortensis and C. nepeta have significant antibacterial activity. Furthermore, the findings of the study are valuable for future investigations focusing on the alternative natural compounds to control plant diseases.
Chrysin Alleviates Salt Stress in Tomato by Physiological, Biochemical, and Genetic Mechanisms
(Elsevier, 2024) Ekinci, Melek; Turan, Metin; Aydin, Murat; Yuce, Merve; Agar, Guleray; Ors, Selda; Yildirim, Ertan
Soil salinity greatly reduces agricultural productivity, especially in dry and semi-arid regions, by interfering with physiological and biochemical processes. This research aimed to determine whether Chrysin (Chr) can mitigate the negative effects of salinity on growth parameters, antioxidant enzyme activity, and gene expression in tomato (Solanum lycopersicum L.) plants. Experiments were conducted in a semi-controlled greenhouse, with plants subjected to varying concentrations of sodium chloride (NaCl) (0 and 100 mM) and Chr (0, 0.1, 0.5, and 1.0 mM). Results revealed that salinity stress significantly reduced plant height, leaf area, and chlorophyll content while increasing hydrogen peroxide (H2O2), malondialdehyde (MDA), and proline levels, indicating oxidative stress. Chr application alleviated these detrimental effects by enhancing the activity of antioxidant enzymes such as catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD), thereby reducing reactive oxygen species (ROS) accumulation. Additionally, Chr treatments improved plant water status and mineral content under salt stress. Gene expression analysis showed that Chr positively regulated the transcription of salt tolerance-related genes, including HKT1-1, HKT1-2, and PIP1-2, which are associated with sodium ion transport and water balance. These findings suggest that Chr can be an effective biostimulant for enhancing salt tolerance in tomato plants by modulating physiological, biochemical, and genetic mechanisms. This study provides insights into Chr's potential as a sustainable solution for improving crop resilience to salinity in agricultural practices. Further research is recommended to optimize Chr concentrations for maximum efficacy.
Chrysin Mitigates Copper Stress by Regulating Antioxidant Enzymes Activity, Plant Nutrient and Phytohormones Content in Pepper
(Elsevier, 2024) Yuce, Merve; Ekinci, Melek; Turan, Metin; Agar, Guleray; Aydin, Murat; Ilhan, Emre; Yildirim, Ertan
Copper (Cu) has an important role in physiological processes. High concentrations of Cu can cause toxic effects for plants. To evaluate the effect of Cu and chrysin (Chr) on the seedling growth, some physiological and biochemical properties of pepper, a factorial experiment in a completely randomized design was carried out. The treatments were T1= Control, T2= 0.1 mM Chr, T3= 0.5 mM Chr, T4= 50 mM Cu, T5= 50 mM Cu+ 0.1 mM Chr and T6= 50 mM Cu+ 0.5 mM Chr. Plant morphological characters were significantly affected by Cu and Chr treatments. The results showed a significant decrease in plant growth parameters due to Cu stress while Chr alleviated negative impacts of Cu on growth these parameters. The hydrogen peroxide (H2O2), malondialdehyde (MDA), prolin and sucrose content increased in pepper seedlings grown under Cu stress conditions. The MDA and H2O2 content showed a decrease with the effect of Chr treatment. Chr treatments also increased prolin and sucrose content of pepper plants under non-stressed conditions. Catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) enzyme activity elevated considerably compared to the control plants under Chr treatments. Moreover, higher values were observed for Chr treated plants under Cu stress. The findings of the study showed that Cu stress lowered all plant nutrient elements except for Cu content. 0.1 and 0.5 mM Chr treatments increased plant nutrient elements content of pepper seedlings under normal and Cu stress conditions. In conclusion, Chr mitigates Cu stress by regulating antioxidant enzymes activity, plant nutrient and phytohormones content in pepper.
The Use of Essential Oils of Origanum Rotundifolium as Antimicrobial Agent Against Plant Pathogenic Bacteria
(Taylor & Francis Ltd, 2016) Gormez, Arzu; Bozari, Sedat; Yanmis, Derya; Gulluce, Medine; Agar, Guleray; Sahin, Fikrettin
In this study, the antibacterial effect of Origanum rotundifolium Boiss's essential oil was evaluated against 20 plant pathogenic bacteria. The essential oil (EO) of O. rotundifolium was hydrodistillated from wild O. rotundifolium plants that grown in Eastern Anatolia region of Turkey. Then, 10 chemical compounds of EO were identified via gas chromatography/mass spectrometry (GC-MS). The main compounds were determined as thymol (40.86 %-GC), carvacrol (43.62 %), p-cymene (5.95 %) and borneol (2.49 %). According to the results of the study, the essential oil of O. rotundifolium exhibits considerable antibacterial effect against pathogenic bacteria that cause significantly crop loss.