Güller Özkan

Güller Özkan


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 September 2023 in Plants
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Journal Article
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baris erenbaris eren
baris eren
ATAras Turkoglu
Aras Turkoglu
Kamil HalilogluKamil Haliloglu
Kamil Haliloglu
Fatih DemirelFatih Demirel
Fatih Demirel
KNKamila Nowosad
Kamila Nowosad
Jan BocianowskiJan Bocianowski
Jan Bocianowski
Numerous factors can impact the efficiency of callus formation and in vitro regeneration in wheat cultures through the introduction of exogenous polyamines (PAs). The present study aimed to investigate in vitro plant regeneration and DNA methylation patterns utilizing the inter-primer binding site (iPBS) retrotransposon and coupled restriction enzyme digestion–iPBS (CRED–iPBS) methods in wheat. This investigation involved the application of distinct types of PAs (Put: putrescine, Spd: spermidine, and Spm: spermine) at varying concentrations (0, 0.5, 1, and 1.5 mM). The subsequent outcomes were subjected to predictive modeling using diverse machine learning (ML) algorithms. Based on the specific polyamine type and concentration utilized, the results indicated that 1 mM Put and Spd were the most favorable PAs for supporting endosperm-associated mature embryos. Employing an epigenetic approach, Put at concentrations of 0.5 and 1.5 mM exhibited the highest levels of genomic template stability (GTS) (73.9%). Elevated Spd levels correlated with DNA hypermethylation while reduced Spm levels were linked to DNA hypomethylation. The in vitro and epigenetic characteristics were predicted using ML techniques such as the support vector machine (SVM), extreme gradient boosting (XGBoost), and random forest (RF) models. These models were employed to establish relationships between input variables (PAs, concentration, GTS rates, Msp I polymorphism, and Hpa II polymorphism) and output parameters (in vitro measurements). This comparative analysis aimed to evaluate the performance of the models and interpret the generated data. The outcomes demonstrated that the XGBoost method exhibited the highest performance scores for callus induction (CI%), regeneration efficiency (RE), and the number of plantlets (NP), with R2 scores explaining 38.3%, 73.8%, and 85.3% of the variances, respectively. Additionally, the RF algorithm explained 41.5% of the total variance and showcased superior efficacy in terms of embryogenic callus induction (ECI%). Furthermore, the SVM model, which provided the most robust statistics for responding embryogenic calluses (RECs%), yielded an R2 value of 84.1%, signifying its ability to account for a substantial portion of the total variance present in the data. In summary, this study exemplifies the application of diverse ML models to the cultivation of mature wheat embryos in the presence of various exogenous PAs and concentrations. Additionally, it explores the impact of polymorphic variations in the CRED–iPBS profile and DNA methylation on epigenetic changes, thereby contributing to a comprehensive understanding of these regulatory mechanisms.

6 October 2021 in Journal of Plant Biochemistry and Biotechnology
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Journal Article
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AHArash Hosseinpour
Arash Hosseinpour
EIEmre Ilhan
Emre Ilhan
GÖGüller Özkan
Güller Özkan
HOHalil Ibrahim Ozturk
Halil Ibrahim Ozturk
Kamil HalilogluKamil Haliloglu
Kamil Haliloglu
KCKağan tolga Cinisli
Kağan tolga Cinisli

29 June 2023 in Agronomy
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Journal Article
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ATAras Turkoglu
Aras Turkoglu
Kamil HalilogluKamil Haliloglu
Kamil Haliloglu
MTMetin Tosun
Metin Tosun
HBHenryk Bujak
Henryk Bujak
baris erenbaris eren
baris eren
Gniewko NiedbałaGniewko Niedbała
Gniewko Niedbała
The use of mutagens in plant breeding is used to create new germplasm, increase agricultural yield, quality, and resistance to diseases and pests. Mutagens are physical or chemical factors that can alter the DNA or RNA structure of an organism, causing mutations above the expected level. One of the most common and potent chemical mutagens is EMS (ethyl-methane sulfonate), which produces point mutations in plants, but to a lesser degree can also cause the loss or deletion of a chromosomal region. This study used inter-primer binding site (iPBS) and coupled restriction enzyme digestion inter-primer binding site (CRED-iPBS) technique analysis to determine the effect of EMS mutagens on methylation rates in wheat genotypes at seedling growth stage. Treatments with five different EMS concentrations (0%; control, 0.1%, 0.2%, 0.3%, and 0.4%) at four different times (0; control, 3, 6, and 9 h) were used. Inter-primer binding site (iPBS) markers were employed to assess genomic instability and cytosine methylation in treated wheat. In seeds treated with EMS at different concentrations and times, the disappearance of regular bands and the formation of new bands due to the effects of the EMS mutagen revealed that genetic diversity exists. The CRED-iPBS analysis revealed that the 3 h + 0.1% EMS treatment produced the highest MspI polymorphism value (19.60%), while the 9 h + 0.1% EMS treatment produced the lowest value (10.90%). The mutagenic effects of EMS treatments had considerable polymorphism on a variety of impacts on the cytosine methylation and genomic instability of wheat. According to the current research, EMS mutagenesis may be a practical method for accelerating breeding programs to produce enough genetic diversity in wheat populations. Mutation-assisted breeding and the subsequent selection of desirable mutants using genetic markers may also be carried out in wheat utilizing an integrated strategy.

14 June 2023 in Agriculture
Verified
Journal Article
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ATAras Turkoglu
Aras Turkoglu
Kamil HalilogluKamil Haliloglu
Kamil Haliloglu
MTMetin Tosun
Metin Tosun
Piotr SzulcPiotr Szulc
Piotr Szulc
Fatih DemirelFatih Demirel
Fatih Demirel
Gniewko NiedbałaGniewko Niedbała
Gniewko Niedbała
Wheat, which is scientifically known as Triticum aestivum L., is a very nutritious grain that serves as a key component of the human diet. The use of mutation breeding as a tool for crop improvement is a reasonably rapid procedure, and it generates a variety that may be used in selective breeding programs as well as functional gene investigations. The present experiment was used to evaluate the potential application of a conventional chemical mutagenesis technique via sodium azide (NaN3) for the germination and seedling growth stage in wheat. Experiments with NaN3 mutagenesis were conducted using four different treatment periods (0, 1, 2, and 3 h) and five different concentrations (0, 0.5, 1, 1.5, and 2 mM). The genomic instability and cytosine methylation of wheat using its seeds were investigated after they were treated. In order to evaluate the genomic instability and cytosine methylation in wheat that had been treated, interprimer binding site (iPBS) markers were used. The mutagenic effects of NaN3 treatments had considerable polymorphism on a variety of impacts on the cytosine methylation and genomic instability of wheat plants. The results of the experiment showed considerable changes in the iPBS profiles produced by the administration of the same treatments at different dosages and at different times. Coupled restriction enzyme digestion interprimer binding site (CRED-iPBS) assays identified changes in gDNA cytosine methylation. The highest polymorphism value was obtained during 1 h + 2 mM NaN3, while the lowest (20.7%) was obtained during 1 h + 1.5 mM NaN3. Results showed that treatments with NaN3 had an effect on the level of cytosine methylation and the stability of the genomic template in wheat plants in the germination stage. Additionally, an integrated method can be used to for mutation-assisted breeding using a molecular marker system in wheat followed by the selection of desired mutants.

29 May 2023 in Genes
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ATAras Turkoglu
Aras Turkoglu
Kamil HalilogluKamil Haliloglu
Kamil Haliloglu
SMSeyed Abolghasem Mohammadi
Seyed Abolghasem Mohammadi
AÖAli Öztürk
Ali Öztürk
PBParisa Bolouri
Parisa Bolouri
BJBita Jamshidi
Bita Jamshidi
Wheat genotypes should be improved through available germplasm genetic diversity to ensure food security. This study investigated the molecular diversity and population structure of a set of Türkiye bread wheat genotypes using 120 microsatellite markers. Based on the results, 651 polymorphic alleles were evaluated to determine genetic diversity and population structure. The number of alleles ranged from 2 to 19, with an average of 5.44 alleles per locus. Polymorphic information content (PIC) ranged from 0.031 to 0.915 with a mean of 0.43. In addition, the gene diversity index ranged from 0.03 to 0.92 with an average of 0.46. The expected heterozygosity ranged from 0.00 to 0.359 with a mean of 0.124. The unbiased expected heterozygosity ranged from 0.00 to 0.319 with an average of 0.112. The mean values of the number of effective alleles (Ne), genetic diversity of Nei (H) and Shannon’s information index (I) were estimated at 1.190, 1.049 and 0.168, respectively. The highest genetic diversity (GD) was estimated between genotypes G1 and G27. In the UPGMA dendrogram, the 63 genotypes were grouped into three clusters. The three main coordinates were able to explain 12.64, 6.38 and 4.90% of genetic diversity, respectively. AMOVA revealed diversity within populations at 78% and between populations at 22%. The current populations were found to be highly structured. Model-based cluster analyses classified the 63 genotypes studied into three subpopulations. The values of F-statistic (Fst) for the identified subpopulations were 0.253, 0.330 and 0.244, respectively. In addition, the expected values of heterozygosity (He) for these sub-populations were recorded as 0.45, 0.46 and 0.44, respectively. Therefore, SSR markers can be useful not only in genetic diversity and association analysis of wheat but also in its germplasm for various agronomic traits or mechanisms of tolerance to environmental stresses.

28 September 2023 in Agronomy
Verified
Journal Article
Open access
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RÇRamazan Çakmakçı
Ramazan Çakmakçı
Kamil HalilogluKamil Haliloglu
Kamil Haliloglu
ATAras Turkoglu
Aras Turkoglu
GÖGüller Özkan
Güller Özkan
ZMZoltan Molnar
Zoltan Molnar
Jan BocianowskiJan Bocianowski
Jan Bocianowski
Intensive agriculture uses continuous chemical fertilizers to increase crop yields, but excessive use of fertilizers leads to environmental pollution, permanent changes in physicochemical conditions in soil ecology, deterioration of soil biological health, leaching of nutrients, surface and groundwater pollution and eutrophication. Plant growth-promoting rhizobacteria (PGPR) are becoming increasingly important for ensuring crop safety, increasing nutrient uptake and output, lowering fertilizer costs, preventing environmental contamination and promoting sustainable agriculture and agricultural resources. Therefore, the purpose of this study was to identify and evaluate the effects of fifteen bacteria strains that were isolated from various acidic rhizospheric soils as biofertilizers on soil biological properties. Growth, yield and quality traits were analyzed, and various PGPR were identified using 16S ribosomal RNA of Turkish oregano. Fifteen bacterial inoculations with 1-aminocyclopropane-1-carboxylate (ACC) deaminase, N2-fixing, P-solubilizing and/or IAA-producing genes were used in the experiment, which was carried out in a randomized block design with five replicates (each with three pots) and a control without inoculation. Increased biological activity in soil inoculated with bacteria with multiple traits was confirmed by high C and N content in microbial biomass, urease, dehydrogenase and acid and alkaline phosphatase activities. Essential oil content, oil yield, thymol and carvacrol contents increased by 0.5–40.1%, 5.9–71.9%, 0.07–16.7% and 0.3–9.2%, respectively, as a result of bacterial inoculation. Oil content ranged from 2.02% to 2.83%; carvacrol (66.1–72.2%) was the main constituent, followed by thymol (14.5–16.9%) and linalool (1.38–3.68%). Two large PGPR groups were formed based on genetic distance analysis. Responses were variable and depended on the inoculant strain and the parameters being evaluated. The results indicate PGPR has clear potential for improving the yield of cultivated aromatic and essential oil plants, such as oregano.