TR Dizin İndeksli Yayınlar / TR Dizin Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7149
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Article Citation - WoS: 2Citation - Scopus: 2Characterization of the Beta1 Gene, Which Might Play a Role in Beta Vulgaris Subsp. Maritima Salt Tolerance(Türkiye Klinikleri Journal of Medical Sciences, 2017) Uysal, Özge; Çakıroğlu, Çiğdem; Koç, Ahmet; Karakaya, Hüseyin ÇağlarSalinity stress has a negative impact on plant growth, which affects homeostasis and productivity. The uptake of nonessential salt ions changes the osmotic balance of the cell and causes dehydration. Higher plants develop salt tolerance mechanisms to avoid dehydration. Sea beet (Beta vulgaris subsp. maritima) is a halophytic ancestor of cultivated sugar beet that displays salt stress tolerance. In this study, we screened a B. vulgaris subsp. maritima cDNA library in Saccharomyces cerevisiae strain Ab11c (ena1Δ, nha1/4Δ, nhx1Δ), which is deficient in sodium transport, to find sodium-detoxifying genes. We identified a cDNA construct, named BETA1, providing salt tolerance to yeast cells. This gene had no previously described function. Intracellular sodium measurements demonstrated no significant differences between yeast cells expressing BETA1 or a sham vector, suggesting that sodium was not effluxed in BETA1-expressing cells. Transcriptionally, BETA1 mRNA levels were induced immediately in leaves and later in the root system in response to the salt stress. Our results suggest that the BETA1 gene is part of the salt tolerance network in B. vulgaris subsp. maritima.Article Citation - WoS: 11Citation - Scopus: 14Proteomic Changes During Boron Tolerance in Barley (hordeum Vulgare) and the Role of Vacuolar Proton-Translocating Atpase Subunit E(Türkiye Klinikleri Journal of Medical Sciences, 2011) Atik, Ahmet Emin; Bozdağ, Gönensin Ozan; Akıncı, Ersin; Kaya, Alaattin; Koç, Ahmet; Yalçın, Talat; Karakaya, Hüseyin ÇağlarBoron is an essential micronutrient for plants and animals; however, it can be toxic when present at high concentrations. The purpose of this study was to understand the mechanisms of boron tolerance in the Turkish barley (Hordeum vulgare) Anadolu cultivar. For this purpose, 2-dimensional electrophoresis (2-DE) was used to screen differentially expressed proteins for both control and boron-stressed Anadolu barley genotypes. Seven proteins were revealed by 2-DE: 1) ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCo large chain), 2) TLP5, a thaumatin-like protein, 3) PR5, a basic pathogenesis-related protein, 4) a RNase S-like protein, 5) a PSI type III chlorophyll a/b-binding protein, 6) a light-harvesting complex I LHC I, and 7) the vacuolar proton-translocating ATPase subunit E protein. These were found to be upregulated in response to boron treatment. Even though the protein encoded by the V-ATPase subunit E gene was overexpressed, its transcript level was downregulated by boron treatment. Heterologous expression of the barley V-ATPase subunit E gene in yeast provided boron resistance to yeast cells. These results indicated that the V-ATPase subunit E gene was functional and conferred tolerance to toxic boron levels in yeast and might play a role in the overall boron tolerance of barley. © TÜBITAK.Article Evidence for the Presence of a Second Electron Donor for the Cytoplasmic Thioredoxins in the Yeast Saccharomyces Cerevisiae(TUBITAK, 2006) Koç, Ahmet; Karakaya, Hüseyin Çağlar; Ünlü, Ercan SelçukIn yeast, the cytoplasmic thioredoxin system is composed of NADPH, thioredoxin reductase-1 (TRR1) and 2 thioredoxin genes (TRX1, TRX2). In this study, using yeast knockout mutants for TRR1, TRX1 and TRX2 genes, the role of the thioredoxin system in methionine sulfoxide reduction was investigated. Cells lacking both TRX1 and TRX2 genes simultaneously were not able to reduce methionine sulfoxides to methionine; however, mutants missing the TRR1 gene were able to reduce methionine sulfoxides to methionine, which showed that electrons could be transferred from NADPH to thioredoxins in the absence of TRR1. Similar results were observed for 3-phosphoadenosine 5-phosphosulfate reduction in the inorganic sulfate assimilation pathway. Results from both assays suggested that yeast cells have additional cytoplasmic thioredoxin reductase activity that could compensate for methionine sulfoxide reduction and sulfate assimilation in the absence of TRR1. This report also constitutes the first evidence that thioredoxins are the in vivo electron donors for methionine sulfoxide reductases in yeast.