Molecular Biology and Genetics / Moleküler Biyoloji ve Genetik
Permanent URI for this collectionhttps://hdl.handle.net/11147/9
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Book Part Citation - WoS: 30Citation - Scopus: 41Nanocarriers for Plant-Derived Natural Compounds(Elsevier Ltd., 2017) Bayraktar, Oğuz; Erdoğan, İpek; Köse, Merve D.; Kalmaz, GülcanNatural products constitute a large fraction in drug discovery processes. The term includes compounds from plants, microorganisms, and animals. Most of the natural products are secondary metabolites derived from plants, which are low in amounts and difficult to isolate. Another issue is the preservation of their bioactivity during process and storage as well as degradation in the gastrointestinal system before reaching circulation. Advances in nanotechnology offer nanoparticles, nanocapsules, and conjugates, which are devoted to site-specific, time-controlled delivery of bioactive agents. Nanoencapsulated systems have the advantage of high drug encapsulation efficiency because of optimized drug solubility in the core, low polymer content compared to other nanoparticulated systems such as nanospheres, drug polymeric shell protection against degradation factors, and the reduction of tissue irritation caused by the polymeric shell. This chapter will discuss nanoencapsulation methods and advances in carrier systems for plant-derived natural compounds.Book Part Citation - WoS: 3Citation - Scopus: 4Physiology of Metabolites(CABI Publishing, 2012) Frary, Amy; Frary, AnneThis chapter provides an overview of recent research on the effects of genotype fruit development and growing conditions on the synthesis and concentrations of the following metabolites in pepper (Capsicum spp.): antioxidants, carotenoids, phenolic compounds, capsaicinoids, flavonoids and vitamin C.Article Citation - WoS: 19Citation - Scopus: 22Absence of Superoxide Dismutase Activity Causes Nuclear Dna Fragmentation During the Aging Process(Academic Press Inc., 2014) Muid, Khandaker Ashfaqul; Karakaya, Hüseyin Çaglar; Koç, AhmetSuperoxide dismutases (SOD) serve as an important antioxidant defense mechanism in aerobic organisms, and deletion of these genes shortens the replicative life span in the budding yeast Saccharomyces cerevisiae. Even though involvement of superoxide dismutase enzymes in ROS scavenging and the aging process has been studied extensively in different organisms, analyses of DNA damages has not been performed for replicatively old superoxide dismutase deficient cells. In this study, we investigated the roles of SOD1, SOD2 and CCS1 genes in preserving genomic integrity in replicatively old yeast cells using the single cell comet assay. We observed that extend of DNA damage was not significantly different among the young cells of wild type, sod1Δ and sod2Δ strains. However, ccs1Δ mutants showed a 60% higher amount of DNA damage in the young stage compared to that of the wild type cells. The aging process increased the DNA damage rates 3-fold in the wild type and more than 5-fold in sod1Δ, sod2Δ, and ccs1Δ mutant cells. Furthermore, ROS levels of these strains showed a similar pattern to their DNA damage contents. Thus, our results confirm that cells accumulate DNA damages during the aging process and reveal that superoxide dismutase enzymes play a substantial role in preserving the genomic integrity in this process.Article Citation - WoS: 7Citation - Scopus: 10Biotechnology for Enhanced Nutritional Quality in Plants(Taylor and Francis Ltd., 2013) Uncu, Ayşe Özgür; Doğanlar, Sami; Frary, AnneWith almost 870 million people estimated to suffer from chronic hunger worldwide, undernourishment represents a major problem that severely affects people in developing countries. In addition to undernourishment, micronutrient deficiency alone can be a cause of serious illness and death. Large portions of the world population rely on a single, starch-rich crop as their primary energy source and these staple crops are generally not rich sources of micronutrients. As a result, physical and mental health problems related to micronutrient deficiencies are estimated to affect around two billion people worldwide. The situation is expected to get worse in parallel with the expanding world population. Improving the nutritional quality of staple crops seems to be an effective and straightforward solution to the problem. Conventional breeding has long been employed for this purpose but success has been limited to the existing diversity in the gene pool. However, biotechnology enables addition or improvement of any nutrient, even those that are scarce or totally absent in a crop species. In addition, biotechnology introduces speed to the biofortification process compared to conventional breeding. Genetic engineering was successfully employed to improve a wide variety of nutritional traits over the last decade. In the present review, progress toward engineering various types of major and minor constituents for the improvement of plant nutritional quality is discussed. © 2013 Copyright Taylor and Francis Group, LLC.Article Citation - WoS: 111Citation - Scopus: 124Salt Tolerance in Solanum Pennellii: Antioxidant Response and Related Qtl(BioMed Central Ltd., 2010) Frary, Anne; Göl, Deniz; Keleş, Davut; Ökmen, Bilal; Pınar, Hasan; Şığva, Hasan Özgür; Yemenicioğlu, Ahmet; Doğanlar, SamiBackground: Excessive soil salinity is an important problem for agriculture, however, salt tolerance is a complex trait that is not easily bred into plants. Exposure of cultivated tomato to salt stress has been reported to result in increased antioxidant content and activity. Salt tolerance of the related wild species, Solanum pennellii, has also been associated with similar changes in antioxidants. In this work, S. lycopersicum M82, S. pennellii LA716 and a S. pennellii introgression line (IL) population were evaluated for growth and their levels of antioxidant activity (total water-soluble antioxidant activity), major antioxidant compounds (phenolic and flavonoid contents) and antioxidant enzyme activities (superoxide dismutase, catalase, ascorbate peroxidase and peroxidase) under both control and salt stress (150 mM NaCl) conditions. These data were then used to identify quantitative trait loci (QTL) responsible for controlling the antioxidant parameters under both stress and nonstress conditions.Results: Under control conditions, cultivated tomato had higher levels of all antioxidants (except superoxide dismutase) than S. pennellii. However, under salt stress, the wild species showed greater induction of all antioxidants except peroxidase. The ILs showed diverse responses to salinity and proved very useful for the identification of QTL. Thus, 125 loci for antioxidant content under control and salt conditions were detected. Eleven of the total antioxidant activity and phenolic content QTL matched loci identified in an independent study using the same population, thereby reinforcing the validity of the loci. In addition, the growth responses of the ILs were evaluated to identify lines with favorable growth and antioxidant profiles.Conclusions: Plants have a complex antioxidant response when placed under salt stress. Some loci control antioxidant content under all conditions while others are responsible for antioxidant content only under saline or nonsaline conditions. The localization of QTL for these traits and the identification of lines with specific antioxidant and growth responses may be useful for breeding potentially salt tolerant tomato cultivars having higher antioxidant levels under nonstress and salt stress conditions.Article Citation - WoS: 7Citation - Scopus: 7The Roles of Thiol Oxidoreductases in Yeast Replicative Aging(Elsevier Ltd., 2010) Hacıoğlu, Elise; Esmer, Işıl; Fomenko, Dmitri E.; Gladyshev, Vadim N.; Koç, AhmetThiol-based redox reactions are involved in the regulation of a variety of biological functions, such as protection against oxidative stress, signal transduction and protein folding. Some proteins involved in redox regulation have been shown to modulate life span in organisms from yeast to mammals. To assess the role of thiol oxidoreductases in aging on a genome-wide scale, we analyzed the replicative life span of yeast cells lacking known and candidate thiol oxidoreductases. The data suggest the role of several pathways in controlling yeast replicative life span, including thioredoxin reduction, protein folding and degradation, peroxide reduction, PIP3 signaling, and ATP synthesis. © 2010 Elsevier Ireland Ltd.