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Öğe The involvement of Antifreeze protein maxi-like and Cold-shock domain-containing protein genes in cold-induced larval diapause and cold-shock treatment of khapra beetle(Pergamon-Elsevier Science Ltd., 2023) Dağeri, Aslı; Kadir, Mohammed Lengichow; Güz, Nurper; Öğreten, Ayhan; Arshad, MuhammadThe khapra beetle, Trogoderma granarium (Everts) (Coleoptera: Dermestideae), is a cosmopolitan and one of the most destructive pests of various stored grains and grain products. This pest is categorized as a quarantine threat in many countries. The larvae undergo diapause that lasts for several years depending on different stress conditions such as temperature, insecticidal applications, starvation, humidity, crowding, and fecal pellets. When conditions are favorable for the development, diapause terminates and the larva continues its development. In the present study, two cold-regulated genes Antifreeze protein maxi-like (TgAFP) and Cold-shock domain-containing protein E1 (TgCSDP) were identified in the cDNA library of T. granarium. Nucleotide sequences of two unigene cDNAs encoding TgAFP and TgCSDP were verified using RT-PCR and RACE-PCR amplifications. Transcriptional regulations of TgAFP and TgCSDP were examined in cold-induced diapause larvae, cold-shocked larvae, and at different developmental stages. Gene expression pattern of TgAFP revealed the highest mRNA levels during pre-diapause (25 degrees C) followed by the larvae exposed to 5 degrees C during the diapause phase. This can be attributable to the protective role of TgAFP against temperature fall. Significant upregulation of TgCSDP at 15 degrees C might indicate its probable chaperone role in toleration for cold-induced diapause. TgAFP level was downregulated after cold-shock treatment (CST), while it was slightly upregulated by recovery, indicating that it might confer tolerance for the recovery period (RP). The highest TgCSDP expression after the CST might suggest its involvement in response to acute CST. Low abundance of TgAFP expression in each developmental stage might suggest that 33 degrees C temperature does not induce the synthesis of TgAFP. Significant amount of TgCSDP levels in adults might indicate its putative role in development. These findings suggest that TgAFP and TgCSDP genes might be crucial for cold survival where the T. granarium undergoes its facultative diapause.Öğe Artificial neural network modeling for deciphering the in vitro induced salt stress tolerance in chickpea (Cicer arietinum L)(Springer, 2023) Aasım, Muhammad; Akın, Fatma; Ali, Seyid Amjad; Taşkın, Mehmet Burak; Çolak, Müslüme Sevba; Khawar, Khalid MahmoodSalt stress is one of the most critical abiotic stresses having significant contribution in global agriculture production. Chickpea is sensitive to salt stress at various growth stages and a better knowledge of salt tolerance in chickpea would enable breeding of salt tolerant varieties. During present investigation, in vitro screening of desi chickpea by continuous exposure of seeds to NaCl-containing medium was performed. NaCl was applied in the MS medium at the rate of 6.25, 12.50, 25, 50, 75, 100, and 125 mM. Different germination indices and growth indices of roots and shoots were recorded. Mean germination (%) of roots and shoots ranged from 52.08 to 100%, and 41.67-100%, respectively. The mean germination time (MGT) of roots and shoots ranged from 2.40 to 4.78 d and 3.23-7.05 d. The coefficient of variation of the germination time (CVt) was recorded as 20.91-53.43% for roots, and 14.53-44.17% for shoots. The mean germination rate (MR) of roots was better than shoots. The uncertainty (U) values were tabulated as 0.43-1.59 (roots) and 0.92-2.33 (shoots). The synchronization index (Z) reflected the negative impact of elevated salinity levels on both root and shoot emergence. Application of NaCl exerted a negative impact on all growth indices compared to control and decreased gradually with elevated NaCl concentration. Results on salt tolerance index (STI) also revealed the reduced STI with elevated NaCl concentration and STI of roots was less than shoot. Elemental analysis revealed more Na and Cl accumulation with respective elevated NaCl concentrations. The In vitro growth parameters and STI values validated and predicted by multilayer perceptron (MLP) model revealed the relatively high R-2 values of all growth indices and STI. Findings of this study will be helpful to broaden the understanding about the salinity tolerance level of desi chickpea seeds under in vitro conditions using various germination indices and seedling growth indices.Öğe Hormetic activation of nano-sized rare earth element terbium on growth, PSII photochemistry, antioxidant status and phytohormone regulation in Lemna minor(Elsevier, 2023) Alp, Fatma Nur; Arıkan, Büşra; Özfidan Konakçı, Ceyda; Gülentürk, Çağrı; Yıldıztugay, Evren; Turan, Metin; Çavuşoğlu, HalitSoils contaminated with rare earth elements (REEs) can damage agriculture by causing physiological disorders in plants which are evaluated as the main connection of the human food chain. A biphasic dose response with excitatory responses to low concentrations and inhibitory/harmful responses to high concentrations has been defined as hormesis. However, not much is clear about the ecological effects and potential risks of REEs to plants. For this purpose, here we showed the impacts of different concentrations of nano terbium (Tb) applications (510-25-50-100-250-500 mg L-1) on the accumulation of endogeneous certain ions and hormones, chlorophyll fluoresence, photochemical reaction capacity and antioxidant activity in duckweed (Lemna minor). Tb concentrations less than 100 mg L (-1) increased the contents of nitrogen (N), phosphate (P), potassium (K+), calcium (Ca2+), magnesium (Mg2+), manganese (Mn2+) and iron (Fe2+). Chlorophyll fluorescence (Fv/Fm and Fv/Fo) was suppressed under 250-500 mg L-1 Tb. In addition, Tb toxicity affected the trapped energy adversely by the active reaction center of photosystem II (PSII) and led to accumulation of inactive reaction centers, thus lowering the detected level of electron transport from photosystem II (PSII) to photosystem I (PSI). On the other hand, 5-100 mg L-1 Tb enhanced the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), NADPH oxidase (NOX), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione S-transferase (GST). Tb (5-50 mg L-1) supported the maintenance of cellular redox status by promoting antioxidant pathways involved in the ascorbateglutathione (AsA-GSH) cycle. In addition to the antioxidant system, the contents of some hormones such as indole-3-acetic acid (IAA), gibberellic acid (GA), cytokinin (CK) and salicylic acid (SA) were also induced in the presence of 5-100 mg L-1 Tb. In addition, the levels of hydrogen peroxide (H2O2) and lipid peroxidation (TBARS) were controlled through ascorbate (AsA) regeneration and effective hormonal modulation in L. minor. However, this induction in the antioxidant system and phytohormone contents could not be resumed after applications higher than 250 mg L-1 Tb. TBARS and H2O2, which indicate the level of lipid peroxidation, increased. The results in this study showed that Tb at appropriate concentrations has great potential to confer tolerance of duckweed by supporting the antioxidant system, protecting the biochemical reactions of photosystems and improving hormonal regulation.Öğe Responses of individual and combined polystyrene and polymethyl methacrylate nanoplastics on hormonal content, fluorescence/photochemistry of chlorophylls and ROS scavenging capacity in Lemna minor under arsenic-induced oxidative stress(Elsevier, 2023) Özfidan Konakçı, Ceyda; Yıldıztugay, Evren; Arıkan, Büşra; Alp Turgut, Fatma Nur; Turan, Metin; Çavuşoğlu, Halit; Şakalak, HüseyinNanoplastics alter the adverse impacts of hazardous contaminants such as heavy metals by changing their adsorption and accumulation. Few findings are available on the interaction between nanoplastic and heavy metals in plants. However, there is no report on the mechanisms for removing metal stress-mediated oxidative damage by the combination treatments of nanoplastics. To address this lack of information, polystyrene nano-plastic (PS, 100 mg L-1) and polymethyl methacrylate (PMMA, 100 mg L-1) were hydroponically applied to Lemna minor exposed to arsenate (As, 100 mu M) for 7 days. PS or PMMA caused a reduction in the contents of N, P, K, Ca, Mg and Mn, but the improved contents were detected in the presence of PS or PMMA plus As stress. The hormone contents (auxin, gibberellic acid, cytokinin, salicylic acid and jasmonic acid) reduced by stress were re-arranged through PS or PMMA applications. Based on chlorophyll efficiency, fluorescence kinetics and performance of PSII, the impaired photosynthesis by As stress was improved via PS or PMMA applications. This alleviation did not continue under the combined form of PS and PMMA in As-applied plants. All analyzed antioxidant activity (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), monodehydroascorbate reduc-tase (MDHAR) and dehydroascorbate reductase (DHAR)) decreased or unchanged under As, PS or PMMA. Due to the inactivation of the defense system, L. minor had high levels of hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS), showing lipid peroxidation. After As toxicity, induvial applications of PS or PMMA indicated the activated enzyme capacity (SOD, POX, GST and GPX) and upregulated AsA/DHA, GSH/ GSSG and redox state of GSH, which facilitated the removal of radical accumulation. The efficiency of the antioxidant system in As + PS + PMMA-applied L. minor was not enough to remove damage induced by As stress; hereby, TBARS and H2O2 contents were similar to the As-treated group. Our findings from alone or combined application of PS and PMMA provide new information to advance the tolerance mechanism against As exposure in L. minor.Öğe Rare earth element scandium mitigates the chromium toxicity in Lemna minor by regulating photosynthetic performance, hormonal balance and antioxidant machinery(Elsevier, 2023) Alp, Fatma Nur; Arıkan, Büşra; Özfidan Konakçı, Ceyda; Ekim, Rumeysa; Yıldıztugay, Evren; Turan, MetinChromium (Cr) toxicity is a serious problem that threatens the health of living organisms and especially agricultural production. The presence of excess Cr leads to biomass loss by causing the imbalance of biochemical metabolism and inhibiting photosynthetic activity. A new critical approach to cope with Cr toxicity is the use of the rare earth elements (REEs) as an antioxidant defence system enhancer in plants. However, the effect of scandium (Sc), which is one of the REEs, is not clear enough in Lemna minor exposed to Cr toxicity. For this purpose, the photosynthetic and biochemical effects of scandium (50 μM and 200 μM Sc) treatments were investigated in Lemna minor under Cr stress (100 μM, 200 μM and 500 μM Cr). Parameters related to photosynthesis (Fv/Fm, Fv/Fo) were suppressed under Cr stress. Stress altered antioxidant enzymes activities and hormone contents. Sc applications against stress increased the activities of superoxide dismutase (SOD), NADPH oxidase (NOX), ascorbate peroxidase (APX), lutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and glutathione S-transferase (GST). In addition to the antioxidant system, the contents of indole-3- acetic acid (IAA), abscisic acid (ABA) and jasmonic acid (JA) were also rearranged. However, in all treatment groups, with the provision of ascorbate (AsA) regeneration and effective hormone signaling, reactive oxygen species (ROS) retention which result in high hydrogen peroxide (H2O2) content and lipid peroxidation (TBARS) were effectively removed. Sc promoted the maintenance of cellular redox state by regulating antioxidant pathways included in the AsA-GSH cycle. Our results showed that Sc has great potential to confer tolerance to duckweed by reducing Cr induced oxidative damage, protecting the biochemical reactions of photosynthesis, and improving hormone signaling.Öğe Antimicrobial and antibiofilm activity of green synthesized silver nanoparticles by using aqueous leaf extract of Thymus serpyllum(2019) Erci, Fatih; Torlak, EmrahRecently, metal nanoparticles have attracted the attention of researchers due to their unique properties whencompared with bulk materials and have become used in many fields of application. In this study, green synthesis ofAg nanoparticles (AgNPs) was investigated by using the aqueous extract of T. serpyllum leaves. In addition,antimicrobial and antibiofilm activities of the synthesized AgNPs were evaluated in this study. Further, ultraviolet-visible spectroscopy (UV-Vis), fouirer transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) and transmission electron microscopy (TEM) were used for characterization of the green synthesized AgNPs. The UV-Vis spectrum of the synthesizedAgNPs had a maximum peak at 467 nm. Also, TEM analysis indicated spherical particles with an average size of 25.2 nm. The synthesized AgNPs have higher stability (zeta potential: -29.5 mV). The antimicrobial activity of thegreen synthesized AgNPs was investigated on both Gram-positive and Gram-negative bacteria, such as Bacilluscereus (B. cereus), Staphylococcus aureus (S. aureus), Escherichia coli (E. coli) and Salmonella enterica serovarTyphimurium (S. Typhimurium) using agar well diffusion assay. According to the results of the study, Gram-positivebacteria showed larger inhibition zones compared to Gram-negative bacteria. Finally, the AgNPs were explored forthe inhibition of S. aureus biofilms. AgNPs at 100 ?g/mL concentration showed a high inhibition value of about 73%for S. aureus biofilm formation. So, it is concluded that the synthesized AgNPs might be potentially used in manyapplications due to their antimicrobial and antibiofilm properties.Öğe High-Throughput Genomic Simple Sequence Repeat (SSR) Marker Development and Construction of a High Resolution Physical Map in Button Mushroom (Agaricus bisporus) Genome(2018) Uncu, Ali Tevfik; Özgür Uncu, AyşeButton mushroom [Agaricus bisporus (J.E. Lange) Imbach], is both a model organism and a worldwide cultivated edible mushroom species. Despite its scientific and economic relevance, efforts to develop molecular markers in A. bisporus genome are scarce and relatively recent. The present research reports the development of 3943 novel simple sequence repeat (SSR) markers specific to the A. bisporus genome. The marker set is well-distributed among the 13 A. bisporus chromosomes, saturating the entire genome with sequence-specific markers. The large number of novel, A. bisporus specific DNA markers introduced in the present work constitute a valuable resource for molecular genetic research in button mushroom, including strain identification and protection, and gene/QTL (Quantitative Trait Locus) mapping.Öğe Çiğ Sütlerde Antibiyotik Kalıntı Analizlerinde Hızlı Test Metotlarının ve HPLC Tekniğinin Değerlendirilmesi(2012) Torlak, Emrah; Gökmen, Mukadderat; Ümit, Gürbüz; Kiztanır, Bünyamin; Işık, Mehmet KürşatBu çalışmada, farklı prensiplere dayalı üç farklı antibiyotik test kitinin performansları beta-laktam grubu antibiyotiklerden penisilin G, ampisilin, amoksisilin ve kloksasilin ile yapay olarak kontamine edilmiş çiğ süt örneklerinde değerlendirildi. Kontamine edilmemiş çiğ süt örneklerinde immunoreseptör ve enzimatik temelli test kitleri ile yanlış pozitif sonuç alınmadı. Bununla beraber, mikrobiyal inhibisyon temelli test kiti ile bir örnekten yanlış pozitif sonuç elde edildi. Türk Gıda Kodeksi maksimum kalıntı limitlerinde en yüksek hassasiyet oranı immunoreseptör temelli test kiti ile elde edildi. Enzimatik temelli test kitinin maksimum kalıntı limitlerindeki performansının yetersiz olduğu tespit edildi. Çalışmada, örnekteki antibiyotik kalıntılarının C18 katı faz ekstraksiyonu, benzoik anhidrit ve 1,2,4-triazol civa klorid solüsyonu ile türevlendirme ve 325 nm dalga boyunda UV ile tespit prensibine dayanan HPLC metodu kullanıldı. Metot tespit limitleri, ampisilin için 8 ?g/kg, amoksisilin için 8 ?g/kg; penisilin G için 6 ?g/kg ve kloksasilin için 11 ?g/kg olarak belirlendi. Ortalama geri kazanımlar % 67.7 ve % 76.6 arasında tespit edildi. Kromatografik metot ile elde edilen tespit limitleri, ampisilin, amoksisilin ve penisilin G için Türkiye ve Avrupa Birliği maksimum kalıntı limitlerinin üzerinde saptandıÖğe Effect of Tween 80 on Conjugated Linoleic Acid Productionby Lactobacillus Strains in Reconstituted Skim Milk Powder(2016) Torlak, Emrah; Yalçın, Suzan; Erci, FatihBu çalışmada üç adet konjuge linoleik asit (KLA) üreten Lactobacillus suşu 2000 µg/ml linoleik asit (LA) ve çeşitli konsantrasyonlarda Tween 80 ilave edilmiş rekonstitüe yağsız süt tozu (%10) içinde 36 saate kadar kültüre edilmiştir. İnkübasyon boyunca kültür süpernatantlarında toplam KLA düzeyleri UV-spektrofotometre ile tespit edilmiştir. KLA düzeyleri 5 ve 20 mg/ml Tween 80 ilavesi ile önemli (P0.05) seviyede artmıştır. Bununla birlikte, Tween 80 konsantrasyonunun 20 mg/ml'den 40 mg/ml'ye arttırılması KLA düzeyinde bir artışa neden olmamıştır. İnkübasyon esnasında Lactobacillus suşlarının gelişme hızı ve KLA üretimlerinde benzer artış oranları gözlenmiştir.Öğe Tüketime Hazır Bazı Gıdalarda Enterococcus spp. Prevalansı, Antibiyotik Dirençlilik ve Virülens Faktörlerinin Tespiti(2017) Gökmen, Mukadderat; Önen, Adem; Ektik, Nisanur; Kara, Recep; Torlak, Emrah; Metli, Murat; Metli, MuratBu çalışmada tüketime hazır bazı gıdalarda Enterokok türlerinin prevalansı, antibiyotik dirençliliği ve virülans faktörleri belirlendi. Analize alınan 187 gıda örneğinin 112 (%59,9)'sinde 114 Enterococcus spp. izole edildi. Et ürünlerinden 39 (%34,8), peynirlerden 42 (%37,5), salatalardan 25'i (%22,3) ve helva örneklerinden 8 (%7,1)'inde Enterococcus spp. izolatı elde edildi. Antibiyotik dirençlilik testi sonuçlarına göre, elde edilen Enterokok izolatlarının çalışmada kullanılan antibiyotiklerden en az dördüne dirençlilik gösterdiği tespit edildi. İzolatların hiçbirinde gelatinaz aktivitesi gözlenmezken, 36'sında (%31,6) hemolizin aktivitesi pozitif tespit edildi. Sonuç olarak starter kültür olarak kullanılabileceği ve insanlar için zararsız olduğu düşünülen bazı Enterokok türlerinin, virülens faktörler ve sahip olabilecekleri antimikrobiyal direnç bakımından halk sağlığı ve gıda güvenliği açısından bir risk oluşturabilmektedir. Bu nedenle gıda endüstrisinde starter olarak kullanılabilecek Enterokok türleri, patojenite özelliği bulunmayan ve antibiyotik direnç genlerine sahip olmayanlardan seçilmelidirÖğe Efficacy of Gaseous Ozone Against Paenibacillus Larvae Spores on Hive Materials(2018) Torlak, Emrah; Işık, Mehmet KürşatAmerican Foulbrood (AFB) is a highly contagious bacterial honey bee disease caused by Paenibacillus larvae. The elimination of P. larvae spores from contaminated hives is a key factor to achieve the long-term success in AFB control. The purpose of this study was to evaluate the efficacy of gaseous ozone in inactivating the P. larvae spores on wooden and plastic hive materials. Untreated pinewood and polyvinyl chloride (PVC) were chosen as representatives for the hive materials. Pinewood and PVC sticks inoculated with a spore cocktail of three P. larvae strains were treated up to 120 min with two different constant concentrations of gaseous ozone (9.8 and 17.1 mg/L) at room temperature. Ozonation at 17.1 mg/L for 120 min yielded over the 4 log reduction in the counts of spores on PVC sticks. Whereas, reduction of 2.3 log was obtained on pinewood sticks under the same experimental conditions. Reductions achieved in the levels of P. larvae spores on PVC sticks after 90 and 120 min of ozonation were significantly (p0.05) higher than those on pinewood sticks. Our results suggest that gaseous ozone treatment is a promising candidate for the sterilization of plastic hives contaminated with P. larvae spores.
