Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

Job Title


Last Name


First Name



Search Results

Now showing 1 - 5 of 5
  • Publication
    The Comparison of P5CS Gene Expressions of Two Soybean Varieties Under Salt Stress
    (2011 In Vitro Biology Meeting, 2011) ATAK, ÇİMEN; ÇELİK, ÖZGE; 113987; 6653
  • Publication
    Differential regulation of antioxidative gene expressions in response to salt stress in rice
    (International Congress on Transcriptomics 27-29 Temmuz 2015, 2015) Candar, Bilgin; ATAK, ÇİMEN; ÇELİK, ÖZGE; 113987; 195745; 6653
    Rice (Oryza sativa L.) is one of the most important crops because it is a nutritional source of more than one-third of the world population. Soil salinity is one of the most important abiotic stress factors that affect plant growth and productivity adversely. Rice growth and yield is also affected by salinity and at the seedling stage although it is known to be susceptible to salinity. Reactive oxygen species are induced by salt stress and some responsive mechanisms are evolved against to the detrimental effects caused by salt stress. Salinity response is especially controlled by obtaining homeostasis between antioxidative mechanisms and accumulation of reactive oxygen species (ROS) produced as a result of oxidative stress caused by salinity. It is known that combined expression profiles of antioxidative system enzymes may provide increased tolerance capacity. Therefore, the expression profiles of antioxidative enzymes in two different rice cultivars which have different salt sensitivities at four different salt stress conditions were determined. Salinity responses of two different rice varieties were investigated at seedling stage. Four different salinity treatments were then applied using Yoshida solution containing 0, 30, 90, 150 and 210 mM NaCl to the nutrient solution for seven days. At the end of the seven days, the leaves were harvested and stored at -20oC for further experiments. The salt stress responsive gene specific primers were amplified by designed primers due to the 3?-UTR regions of each of the following genes by aligning all available related genes in the databases of NCBI and KOME: Mn-SOD, Cu/Zn-SOD, Fe-SOD, Cytosolic APX, Thylakoid-bound APX, stromal APX, Cytosolic GR and CatA. Mn-SOD was consisted with the trend of variation in SOD activities of rice varieties. The expression patternof CAT A gene was markedly decreased compared to control in both rice varieties. Str-APX gene expression was up-regulated during salt stress treatments in both rice varieties. Transcript levels of Cyt-APX and Thy-APX were up-regulated in accordance with increasing salt stress in Osmanc?k-97 variety. The expression pattern of gene encoding enzyme Cyt-GR1 showed a gradual up-regulation as a response to subjected increasing NaCl stress in Mevl�tbey variety while only after 90 mM treatment, an up-regulation was observed for Osmanc?k variety. These data indicated that the antioxidative responses of salt tolerant and salt sensitive rice varieties are differentially regulated.
  • Publication
    Tissue-specific transcriptional regulation of seven heavy metal stress-responsive miRNAs and their putative targets in nickel indicator castor bean (R. communis L.) plants
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA, 2019-04-15) Akdaş, Enes Yağız; ÇELİK, ÖZGE
    R.communis L. has high capability to accumulate nickel which is a trace nutrient for higher plants and also an environmental contaminant causes toxicity related symptoms at higher concentrations. MicroRNAs (miRNAs) are known to be important modulators of responses against heavy metal stress for detoxification of the metal. In this study, we experimentally measured and validated the transcript levels of the seven heavy metal stress response-related miRNAs and the expression levels of target genes in both leaf and root tissues of R. communis L. subjected to three different concentrations of nickel stress via qRT-PCR quantification. The results demonstrated differential regulations of heavy metal stress-responsive miRNAs and their putative targets in both tissues in same stress treatments. This dynamic regulation suggest that regulatory processes differ between the tissues under nickel stress. Our data suggest that, miR838 was the most responsive to the Ni2+ stress. miR398 target gene Cu-Zn/SOD was found to be up-regulated in both root and leaf tissues. The relations between TCP and expression levels of miR159 and miR319 were also found statistically significant exclusive to leaf tissues. In leaf tissue, changes in miR395 level and its putative target genes, sulphate transporter and sulphate adenyltransferase gene were found in relation whereas, only expression level of sulphate transporter represented a statistically significant relation in root tissue. The sharp decrease in transcript levels of 2r3 myb gene at lower nickel dose suggest to investigate the role of r2r3 myb and the all MYB family members in primary and secondary metabolisms against nickel stress.
  • PublicationEmbargo
    Response of soybean plants to gamma radiation: Biochemical analyses and expression patterns of trichome development
    (2014) Suludere, Zekiye; ATAK, ÇİMEN; ÇELİK, ÖZGE; 6653; 113987; 4019
    This is the first report on soybean with the aim to show the effects of gamma radiation on trichome metabolim. Soybean seeds were subjected to 300 Gy gamma radiation at a dose rate of 10 Gy/min using a Cs-137 gamma source. The photosynthetic pigment, total protein content and ascorbate peroxidase activity were studied. The results showed that the chlorophyll a content was decreased by 80% on day 14 and by 77% on day 21 of irradiation. The chlorophyll b content was reduced by 58.6% and 62.06% on day 14 and 21 after irradiation, respectively. The total carotenoid concentration was reduced by 81.14% on the 14th day after irradiation and by 91% on the 21st day of irradiation, compared to control. The total protein concentration was found to have decreased significantly at 14 and 21 day after treatment. High level of ascorbate peroxidase (APX) activity was recorded in the leaves developed from irradiated soybean seeds, compared to the non-irradiated group. The trichome densities were 6.76 fold increased at 21 day of irradiation, while the stomatal densities were decreased, compared to control. We also performed a qRT-PCR analysis to detect the transcription levels of the soybean trichome developmental genes. The GL2 and CPC genes were up-regulated (P≤0.05). The results of this study pointed out that the CPC transcription factor has to be study in further studies to provide an insight on its exact role in regulation of trichome development in soybean under radiation stress.
  • Publication
    Expression Analysis of Proline Metabolism-Related Genes in Salt-Tolerant Soybean Mutant Plants
    (Southern Cross Publ, 8 91-93 Mckenzie St, Lismore, Nsw 2480, Australia, 2013-09) Ünsal, Selin Gül; ÇELİK, ÖZGE; 113987
    Salt stress is one of the important abiotic stress factors. Proline is generally thought to play an important role in the improvement of salt tolerance in plants. In the present study, we discussed the relationship between free proline accumulation and the expression patterns of the genes that play roles in proline metabolism (P5CS, P5CR, PDH, P5CDH) under 90 mM NaCl stress. We used three salt tolerant M3 generation soybean mutant plants (Ataem-7/150-68, S04-05/150-2 and S04-05/150-114). The mutants belonging to M3 generation are determined as tolerant to 90 mM NaCl. The free proline contents of the salt-tolerant mutants were measured at the upper phase of the extract with respect to toluene. We observed 1.96-, 2.43- and 1.14-fold increases in the free proline accumulation of Ataem-7/150-68, S04-05/150-2 and S04-05/150-114 mutant plants after 7 days of salt treatment in accordance with control groups, respectively. The expression analyses were performed using specific primers designed for soybean gene regions. According to the results of the quantitative reverse-transcriptase polymerase chain reaction, all the genes were up-regulated when these mutants were subjected to salt stress. In addition to increased expression levels of these genes in three salt tolerant soybean mutants, the only statistically significant relation was observed between the regulation of P5CR and PDH gene expressions and proline content in S04-05/150-114 mutant. In further studies, the other possible mechanisms that cause proline accumulation should be evaluated for these salt tolerant soybean mutants.