Browsing by Author "Kavas M."

Now showing 1 - 9 of 9

Antioxidative and physiological responses of two sunflower (Helianthus annuus) cultivars under PEG-mediated drought stress
(2012-11-12) Baloǧlu M.C.; Kavas M.; Aydin G.; Öktem H.A.; Yücel A.M.
Drought stress is one of the most important yield-reducing factors in crop production. Sunflower, an oilseed crop, is severely affected by abiotic stress. In this study, 2 sunflower cultivars (Musala and Aydi{dotless}n) were evaluated in terms of various biochemical and physiological responses under 2 different polyethylene glycol-mediated drought stress conditions. Stress-determining parameters such as malondialdehyde (MDA), hydrogen peroxide (H2O2), and proline contents were determined. Both cultivars showed similar responses at osmotic potentials of both -0.4 and -0.8 MPa. Aydi{dotless}n was less affected than Musala under these stress conditions. MDA, H2O2, and proline levels were similar at both -0.4 and -0.8 MPa osmotic potentials in the 2 different cultivars. The 2 cultivars differed significantly in ascorbate peroxidase and catalase enzyme activities, which were more prominent in Aydi{dotless}n for both stress levels. However, glutathione reductase activity did not appear to be an essential part of the antioxidative system in either of the cultivars. Engineering antioxidative enzyme levels might provide a potential mechanism to cope with drought stress in sunflower. © TÜBİTAK.
Diverse expression pattern of wheat transcription factors against abiotic stresses in wheat species
(2014-10-15) Baloglu M.C.; Inal B.; Kavas M.; Unver T.
Abiotic stress including drought and salinity affects quality and yield of wheat varieties used for the production of both bread and pasta flour. bZIP, MBF1, WRKY, MYB and NAC transcription factor (TF) genes are the largest transcriptional regulators which are involved in growth, development, physiological processes, and biotic/abiotic stress responses in plants. Identification of expression profiling of these TFs plays a crucial role to understand the response of different wheat species against severe environmental changes. In the current study, expression analysis of TaWLIP19 (wheat version of bZIP), TaMBF1, TaWRKY10, TaMYB33 and TaNAC69 genes was examined under drought and salinity stress conditions in Triticum aestivum cv. (Yuregir-89), Triticum turgidum cv. (Kiziltan-91), and Triticum monococcum (Siyez). After drought stress application, all five selected genes in Kiziltan-91 were induced. However, TaMBF1 and TaWLIP19 were the only downregulated genes in Yuregir-89 and Siyez, respectively. Except TaMYB33 in Siyez, expression level of the remaining genes increased under salt stress condition in all Triticum species. For determination of drought response to selected TF members, publicly available RNA-seq data were also analyzed in this study. TaMBF1, TaWLIP19 and TaNAC69 transcripts were detected through in silico analysis. This comprehensive gene expression analysis provides valuable information for understanding the roles of these TFs under abiotic stresses in modern wheat cultivars and ancient einkorn wheat. In addition, selected TFs might be used for determination of drought or salinity-tolerant and susceptible cultivars for molecular breeding studies. © 2014 Elsevier B.V.
Effect of drought stress on oxidative damage and antioxidant enzyme activity in melon seedlings
(2013-08-06) Kavas M.; Baloǧlu M.; Akça O.; Köse F.; Gökçay D.
Drought stress is one of the most serious environmental limitations affecting the growth and productivity of plants. In the current study, oxidative damage and antioxidant responses under polyethylene glycol (PEG)-induced osmotic stress were compared in 2 melon cultivars, Ki{dotless}rkaǧaç and Galia. Melon seedlings were subjected to PEG-6000 solutions of 2 different osmotic potentials, -0.2 MPa and -0.4 MPa. Various physiological parameters, malondialdehyde (MDA), proline content, and antioxidant enzymes including catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were measured. A reduction in fresh and dry weights of shoot and root tissues was observed. Significant proline accumulation was detected with increasing osmotic potential for both cultivars. A significant rise in MDA was detected in Ki{dotless}rkaǧaç at -0.4 MPa osmotic potential. In Galia hydrogen peroxide (H2O2) content increased significantly as PEG concentration increased. CAT showed significantly increased activity only at -0.4 MPa osmotic potential in both cultivars. PEG-induced osmotic stress altered GR activity in both cultivars. These results suggest that (i) Galia is more tolerant than Ki{dotless}rkaǧaç, and (ii) drought tolerance in both cultivars might be closely related to an increase in capacity for antioxidant enzyme activity and the osmoprotective function of proline. Comparing these responses will help to identify drought tolerance mechanisms in melon cultivars. © TÜBITAK.
Effect Of Drought Stress On The Antioxidant Systems Of Two Sunflower Heliantus Annuus Cultivars
(2006) Kavas M.; Kalemtas G.; Çelikkol Akcay U.; Bayrac A.T.; Ozgur E.; Baloglu Mc; Ercan O.; Yucel M.; Oktem H.A.
Enhanced salt tolerance of transgenic tobacco expressing a wheat salt tolerance gene
(2016-01-01) Kavas M.; Baloğlu M.C.; Yücel A.M.; Öktem H.A.
Soil salinity is one of the most important limiting factors of agricultural productivity in the world. The Triticum aestivum salt tolerance-related gene (TaSTRG) possesses a functional response to salt and drought stress conditions. A variety of stress factors, such as salt, drought, abscisic acid, and cold, may induce the expression of TaSTRG in wheat. In this study, the TaSTRG gene was transferred to tobacco via Agrobacterium-mediated transformation. Overexpression of TaSTRG in transgenic tobacco plants indicated higher salt tolerance and mediated more vigorous growth than in wild-type plants. Under salt stress conditions, the transgenic tobacco plants had higher germination and survival rates and longer root length than the control plants. Under salt treatments (200–250 mM), TaSTRGoverexpressing tobacco plants accumulated a higher amount of proline and had significantly lower malondialdehyde content than wild-type plants. Furthermore, transgene inheritance followed Mendelian laws, indicating the stability of TaSTRG in transgenic tobacco plants. These results indicated that the wheat TaSTRG gene plays an important role in responding to salt stress.
Genome-wide characterization and expression analysis of common bean bHLH transcription factors in response to excess salt concentration
(2016-02-01) Kavas M.; Baloğlu M.; Atabay E.; Ziplar U.; Daşgan H.; Ünver T.
Members of basic helix-loop-helix (bHLH) gene family found in all eukaryotes play crucial roles in response to stress. Though, most eukaryotes carry the proteins of this family, biological functions of the most bHLH family members are not deeply evaluated in plants. In this study, we conducted a comprehensive genome-wide analysis of bHLH transcription factors in salt tolerant common bean. We identified 155 bHLH protein-encoding genes (PvbHLH) by using in silico comparative genomics tools. Based on the phylogenetic tree, PvbHLH genes were classified into 8 main groups with 21 subfamilies. Exon–intron analysis indicated that proteins belonging to same main groups exhibited a closely related gene structure. While, the PvbHLH gene family has been mainly expanded through segmental duplications, a total of 11 tandem duplication were detected. Genome-wide expression analysis of bHLH genes showed that 63 PvbHLH genes were differentially expressed in at least one tissue. Three of them displayed higher expression values in both leaf and root tissues. The in silico micro-RNA target transcript analyses revealed that totally 100 PvHLH genes targeted by 86 plant miRNAs. The most abundant transcripts, which were targeted by all 18 plant miRNA, were belonging to PvHLH-22 and PvHLH-44 genes. The expression of 16 PvbHLH genes in the root and leaf tissues of salt-stressed common bean was evaluated using qRT-PCR. Among them, two of PvbHLHs, PvbHLH-54, PvbHLH-148, were found to be up-regulated in both tissues in correlation with RNA-seq measurements. The results of this study could help improve understanding of biological functions of common bean bHLH family under salt stress. Additionally, it may provide basic resources for analyzing bHLH protein function for improving economic, agronomic and ecological benefit in common bean and other species.
Genome-wide investigation and expression analysis of AP2-ERF gene family in salt tolerant common bean
(2015-11-27) Kavas M.; Kurt Kızıldoğan A.; Gökdemir G.; Baloğlu M.
Apetala2-ethylene-responsive element binding factor (AP2-ERF) superfamily with common AP2-DNA binding domain have developmentally and physiologically important roles in plants. Since common bean genome project has been completed recently, it is possible to identify all of the AP2-ERF genes in the common bean genome. In this study, a comprehensive genome-wide in silico analysis identified 180 AP2-ERF superfamily genes in common bean (Phaseolus vulgaris). Based on the amino acid alignment and phylogenetic analyses, superfamily members were classified into four subfamilies: DREB (54), ERF (95), AP2 (27) and RAV (3), as well as one soloist. The physical and chemical characteristics of amino acids, interaction between AP2-ERF proteins, cis elements of promoter region of AP2-ERF genes and phylogenetic trees were predicted and analyzed. Additionally, expression levels of AP2-ERF genes were evaluated by in silico and qRT-PCR analyses. In silico micro-RNA target transcript analyses identified nearly all PvAP2-ERF genes as targets of by 44 different plant species’ miRNAs were identified in this study. The most abundant target genes were PvAP2/ERF-20-25-62-78-113-173. miR156, miR172 and miR838 were the most important miRNAs found in targeting and BLAST analyses. Interactome analysis revealed that the transcription factor PvAP2-ERF78, an ortholog of Arabidopsis At2G28550, was potentially interacted with at least 15 proteins, indicating that it was very important in transcriptional regulation. Here we present the first study to identify and characterize the AP2-ERF transcription factors in common bean using whole-genome analysis, and the findings may serve as a references for future functional research on the transcription factors in common bean.
Kuraklık Stresinin Kavun Cucumis Melo L Antioksidatif Savunma Sistemi Üzerindeki Etkisi
(2009) Ercan O.; Baloglu Mc; Kavas M.; Gökçay D.; Köse F.S.; Öktem H.A.; Yücel M..
Vector construction strategies for transformation of wheat plant
(2013-07-08) Baloglu M.; Battal A.; Aydin G.; Eroglu A.; Oz M.; Kavas M.; Oktem H.; Yucel M.
Gene cloning and vector construction for plant genetic transformation are routine procedures in plant functional genomic studies. The availability of effective transformation vector is one of the pre-requisites for plant transformation studies. Here, we describe the construction of a series of transformation vectors through different genetic engineering techniques for wheat transformation. For this purpose, NAC-type transcription factor genes TaNAC69-1andTtNAM-B2 were isolated from T. aestivum and T. turgidum, respectively. Then they were cloned into different types of cloning and expression vectors. Besides traditional restriction enzyme digestion and ligation method, Gateway cloning technology which is a fast and reliable alternative cloning method were used for construction of wheat transformation vectors. The transformation vectors constructed in this study are suitable for use in both particle bombardment (biolistic) and Agrobacterium based transformation protocols for wheat plant.