Fen Edebiyat Fakültesi / Faculty of Letters and Science
Permanent URI for this collectionhttps://hdl.handle.net/11727/1396
Browse
6 results
Search Results
Item Identification and expression profiling of toxic boron-responsive microRNAs and their targets in sensitive and tolerant wheat cultivars(2021) Kayihan, Doga Selin; Aksoy, Emre; Kayihan, Ceyhun; 0000-0003-1684-4147; AAW-8352-2021Post transcriptional gene regulation in wheat cultivars caused by boron (B) toxicity has not been reported to date. In this study, two wheat cultivars Bolal-2973 (B-tolerant) and Atay-85 (B-sensitive) were compared with regard to the transcriptional regulation of miR319, miR172 and miR398 and their plausible target genes in order to address differences in their performances under high B levels. The expression levels of Cu/ZnSOD gene were found to be greater in Atay exposed to toxic B compared to Bolal, as verified by stable expression level of miR398. In wheat cultivars, both toxic B concentrations might cause an induction of leaf senescence mechanism due to stable level of JA and ethylene-related miRNAs, miR172 and miR319. miR172 targeting transcription factor TOE1 was only induced under B toxicity in sensitive cultivar Atay. However, MY133 as target of miR319 was significantly upregulated under toxic B in both cultivars. Also, computational prediction of these miRNA targets in wheat was performed and their orthologs in Arabidopsis thaliana were determined. Functional protein association networks of proteins encoded by miRNA targets and gene ontology enrichment analyses of these genes were identified. We identified new sets of genes that are targets of miR172, miR319 and miR398 in T. aestivum. In addition, miR172, miR319 and miR398 are responsive to different nutrient deficiencies or toxicities such as Fe, P, B, S and Cu, suggesting crosstalk between the post-transcriptional regulatory mechanisms involving miRNAs in plants.Item The role of microRNAs in recovery rates of Arabidopsis thaliana after short term cryo-storage(2020) Ekinci, Muhammad Hamit; Kayihan, Doga Selin; Kayihan, Ceyhun; Ciftci, Yelda Ozden; 0000-0003-1684-4147; Q-4515-2016Key message The alteration of expression levels of cold- and oxidative stress-induced genes related-miRNAs play a crucial role in development of successful cryopreservation protocols. Cryopreservation is a safe and cost-effective long-term storage technique which helps to conserve plant germplasm in liquid nitrogen (LN). However, up to now, the molecular regulatory mechanisms that effect survival after cryopreservation have not been satisfactorily elucidated in plants. Thus, the aim of the study concerned to reveal out microRNA (miRNA)-based post-transcriptional regulations during different stages of cryopreservation in 48-h and 72-h in vitro germinated Arabidopsis thaliana since miRNAs not only regulate gene expression in developmental process of plants, but also control transcription in stress conditions by post-transcriptional degradation. Among the screened 10 miRNAs and their selected target genes, differential expression levels were detected in two tested germination time according to exposure of cryopreservation stages, as 6 miRNAs (miR393, miR397, miR398, miR159, miR169 and miR172) showed a mixed pattern in 48-h germinated seedlings while 6 miRNAs (miR397, miR398, miR159, miR169, miR172 and miR408) were significantly down-regulated in OD (Osmoprotection-Dehydration) and LD (Liquid nitrogen-Dilution) samples in comparison to control in 72-h germinated ones. The most striking expression change was obtained in miR393 as it was up-regulated 15-fold in LN treated 48-h seedlings while relatively lower amount induction (twofold) was recorded in cryopreserved 72-h seedlings. The concominant down-regulation of its target TIR1 and HOS1 expression and up-regulation of CBF1 and CBF3 and their downstream genes (COR15 and COR47) were also observed in cryopreserved 48-h germinated seedlings. Thus, the alteration of expression levels of cold-induced genes related-miRNAs plays a crucial role for successful cryopreservation.Item Transgenic tobacco plants overexpressing a cold-adaptive nitroreductase gene exhibited enhanced 2,4-dinitrotoluene detoxification rate at low temperature(2020) Kayihan, Doga Selin; Kayihan, Ceyhun; Ciftci, Yelda Ozden; 0000-0003-1684-4147; 32643388; Q-4515-2016Plants encounter many environmental factors such as low and high temperatures during phytoremediation processes. In this study, our aim was to produce the transgenic tobacco plants by using a newly characterized bacterial nitroreductase,Ntr, which was active at a broad range temperature in order to detoxify 2,4-dinitrotoluene (2,4-DNT) at lower temperature. The presence ofNtrand its heterologous expression was verified in T1 transgenic plants and their growing ability were determined under toxic amount of 2,4-DNT (35 mu M). Fresh weight and dry weight of transgenic plants were significantly higher than wild type (WT) under toxic 2,4-DNT at 22 degrees C, indicating higher growth capacity of the transgenics. Transgenic plants also showed a higher tolerance than WT when exposed to 2,4-DNT at 15 degrees C. Moreover, transformation rate of 2,4-DNT was gradually decreased through decreasing temperatures in WT media, however, it was increased through decreasing temperatures in transgenic plant TR3-25 media and it had the highest transformation rate (54%) of 2,4-DNT at 4 degrees C. Correlatively, 2,4-DNT treatment at 4 degrees C led to a significant decrease in H(2)O(2)level in transgenic plants. Thus, transgenic plants overexpressing nitroreductase might have an important advantage for phytoremediation of toxic nitroaromatic compounds in field applications at low temperatures.Item Moderate level of toxic boron causes differential regulation of microRNAs related to jasmonate and ethylene metabolisms in Arabidopsis thaliana(2019) Kayihan, Doga Selin; Kayihan, Ceyhun; Ciftci, Yelda Ozden; 0000-0003-1684-4147; Q-4515-2016Earlier our colleagues detected that the genes related to jasmonate (JA), ethylene, and cell wall modification were significantly regulated under boron (B) toxicity in wheat. Determination of regulation mechanisms of these novel genes under B toxicity is very important in Arabidopsis thaliana as a model plant. As key regulators, the microRNAs (miRNAs) regulate gene expression at the posttranscriptional level and respond to numerous abiotic stresses in plants. In this study, expression levels of miRNAs such as miR159, miR172, miR319, and miR394 targeting JA and ethylene-related transcription factors and also miR397 targeting laccase were determined in Arabidopsis thaliana under toxic B conditions. Stem-loop quantitative reverse transcription polymerase chain reaction was used to amplify mature miRNAs for expression analyses. Expression levels of miRNAs targeting transcription factors related to JA and ethylene metabolisms were induced remarkably in moderate B toxicity (condition 1B) but not in severe B toxicity (condition 3B). Most remarkable regulations were obtained in miR172 and miR319 in Arabidopsis thaliana. Expression level of miR397 did not remarkably change under B toxicity, indicating a lack of posttranscriptional regulation of laccase related to cell wall modification. Moreover, miRNAs targeting transcription factors related to JA and ethylene metabolisms might be oxidative stress-adaptive responses of Arabidopsis to B toxicity.Item Biotization of In Vitro Plants with Endophytic Beneficial Bacterium (PGP_invit) to Understand Plant-bacteria Interaction(2019) Turkolmez, Nil; Albayrak, Merve; Batool, Maria; Kayihan, Doga Selin; Ekinci, Hamit; Akkaya, Ozlem; Seker, Mine Gul; Kayihan, Ceyhun; Aydinoglu, Fatma; Ciftci, Yelda OzdenItem Regulation of boron toxicity responses via glutathione-dependent detoxification pathways at biochemical and molecular levels in Arabidopsis thaliana(2019) Kayihan, Doga Selin; Kayihan, Ceyhun; Ciftci, Yelda Ozden; 0000-0002-9799-3648; Y-6244-2018The fine-tuned regulation of the Halliwell-Asada cycle (ascorbate-glutathione pathway) in Arabidopsis thaliana under boron (B) toxicity was shown in our previous report. In this study, we investigated the expression levels of some members of the glutathione S-transferase (GST) superfamily, such as phi (GSTF2, GSTF6, GSTF7, and GSTF8), tau (GSTU19), and zeta (GSTZ1) classes in Arabidopsis thaliana that were exposed to 1 mM boric acid (1B) and 3 mM boric acid (3B). Additionally, the expression levels of genes for glutathione (GSH) and phytochelatin biosynthesis as well as miR169 and miR156 were evaluated in Arabidopsis thaliana exposed to 1B and 3B. Moreover, changes in the levels of total GST activity; GSH; and total, protein-bound, and nonprotein thiols were spectrophotometrically determined. GSH levels and nonprotein thiol content did not change significantly following both B-toxicity conditions. Expression levels of GSH1 and GSH2 stayed stable under 1B toxicity; however, GSH1 expression increased significantly under 3B conditions in Arabidopsis thaliana. The expression levels of four genes from phi class members of GST were not dramatically changed under B-toxicity conditions. However, the transcript levels of miR169, ATGSTU19, and ATGSTZ1 were significantly increased after 1B and 3B exposure. These GST genes may have a role in the dramatic increase of total GST activity under toxic B. To the best of our knowledge, this is the first report displaying an integrative view of high-B-induced regulation of GSH-dependent enzymatic machinery at different biological organization levels in Arabidopsis thaliana.