Ahmet Uludag

Cross Resistance of Acetyl-CoA Carboxylase (ACCase) Inhibitor-Resistant Wild Oat (Avena fatua) biotypes in the Pacific Northwest

Seeds from five suspected acetyl-CoA carboxylase (ACCase) inhibitor–resistant wild oat biotypes (R1 to R5) were collected in wheat and lentil fields in the Pacific Northwest. Based on whole plant dose–response experiments, the five resistant biotypes were 2 to 24 times more resistant to the aryloxyphenoxypropionate (APP) herbicides (fenoxaprop, diclofop, and quizalofop) compared with the susceptible biotype. However, none of the resistant biotypes were resistant to the cyclohexanedione (CHD) herbicides, sethoxydim and clethodim. R2 was the only biotype resistant to tralkoxydim and pinoxaden, a phenylpyrazolin herbicide and an ACCase inhibitor. The R2 biotype was 35 and 16 times more resistant to tralkoxydim and pinoxaden, respectively, when compared with the susceptible biotype. The levels of resistance and cross-resistance patterns varied among biotypes indicating either more than one mechanism of resistance or different resistance mutations in these wild oat biotypes. The CHD herbicides, sethoxydim and clethodim, could be used to control these resistant biotypes. Except for the R2 biotype, pinoxaden could be used to control the resistant wild oat biotypes. The resistance patterns of these wild oat biotypes are an indication of the difficulty in predicting cross-resistance among the ACCase inhibitor herbicides. Nomenclature: Clethodim, diclofop, fenoxaprop, pinoxaden, quizalofop, sethoxydim, tralkoxydim, wild oat, Avena fatua L. AVEFA, lentil, Lens culinaris Medik, wheat, Triticum aestivum L

Increased T-Allele Frequency of 677 C>T Polymorphism in the Methylenetetrahydrofolate Reductase Gene in Differentiated Thyroid Carcinoma

BACKGROUND Epigenetic alterations in the global DNA methylation status may be associated with an increased risk of some cancer types in humans. The methylenetetrahydrofolate reductase (MTHFR) gene is involved in folic acid metabolism and plays an essential role in inherited DNA methylation profiles. The common 677 C>T and 1298 A>C polymorphisms in the MTHFR gene cause the production of a thermolabile enzyme with reduced function and, eventually, genomic DNA hypomethylation. The current preliminary study was designed to determine the association between germ-line polymorphism in the MTHFR gene and differentiated thyroid carcinoma (DTC). METHODS In the current case-control study of 60 thyroid carcinomas (TC); 45 papillary TC, 9 follicular TC, and 6 DTC of an uncertain malignant potential were examined. Genomic DNA was extracted from peripheral blood with EDTA, genotyped by a multiplex real-time polymerase chain reaction. RESULTS An elevated 2.33-fold risk was observed for DTC in individuals with the 677TT genotype when compared with the control group (odds ratio [OR]: 1.92, 95% confidence interval [CI]: 1.03-3.58). Current DTC patients showed similar results as a control group for the 1298 A>C allele. No significant risk was detected for the homozygous 1298CC genotype (CC vs. AA or AC) (OR: 1.30, 95% CI: 0.73-2.29). CONCLUSION The current results are supportive of the hypothesis that the homozygous MTHFR 677TT genotype increases the risk factor of developing thyroid cancer, and further large-scale studies are needed to validate this association.

Association between ABCB1 (MDR1) Gene 3435 C>T Polymorphism and Colchicine Unresponsiveness of FMF Patients

The multidrug resistance gene-1 (MDR1, adenosine triphosphate-binding cassette transporter: ABCB1, P-glycoprotein) encodes membrane proteins that play a crucial role in protecting cells from xenobiotics, chemicals, and drugs. The TT genotype of 3435 codon in exon 26 of MDR1 gene causes overexpression of gene activity and effluxes many chemically diverse compounds across the plasma membrane. We studied the association between C3435T polymorphisms (single nucleotide polymorphism) of MDR1 gene and colchicine-resistant familial Mediterranean fever (FMF) patients. Total genomic DNA samples from 52 FMF patients of colchicine unresponsiveness were used for FMF (MEFV) and MDR1 genes profile analyses. Target genes were genotyped by multiplex PCR-based reverse-hybridization Strip Assay method. The preliminary current results showed increased T allele frequency (0.596) in colchicine unresponsiveness of FMF patients. The distributions of the CC, CT, and TT genotypes in colchicine nonresponder FMF patients were 17%, 46%, and 37%, respectively. Our results indicate that C3435T polymorphism in exon 26 of MDR1 gene is associated with colchicine resistance in nonresponder FMF patients during the common therapy protocol.

Germ-line MTHFR C677T, FV H1299R and PAI-1 5G/4G Variations in Breast Carcinoma

BACKGROUND Various oncogenes related to cancer have been extensively studied and several polymorphisms have been found to be associated with breast cancer. The current report outlines analysis of germ-line polymorphisms for C677T, A1298C (MTHFR), Leiden, R2 (FV) and 5G/4G (PAI-1) in Turkish breast cancer patients. We studied 51 cases diagnosed with invasive ductal and operable with lymph node-positive breast cancer and 106 women as a control group. MATERIALS AND METHODS Peripheric blood-DNA samples were used for genotyping by StripAssay technique which is based on the reverse-hybridization principle and real-time PCR methods and results were compared statistically. RESULTS The frequency of the MTHFR gene 677T and 1298A alleles were significantly higher in cancer patients than in the healthy subjects. The T allele frequency in codon 677 was 2.3-fold and C allele frequency was 3.1-fold increased in BC when compared to the control group for the MTHFR gene. Both differences were statistically significant (OR: 2.295, CI: 1.283-4.106), p<0.006 and (OR: 3.131, CI:1.826-5.369), p<0.0001 respectively. The R2 allele frequency of FV gene was 5.1-fold increased in the current BC when compared to the control group and that difference was also statistically significant (OR: 5.133, CI: 1.299-20.28), p<0.02. CONCLUSIONS The present data suggest that germ-line polymorphisms of C677T, C1298A for MTHFR and R2 for FV are associated in breast cancer and may be additional prognostic markers related to breast cancer survival. The results now need to be confirmed in a larger group of patients.

Possible Roles of the Xenobiotic Transporter P-glycoproteins Encoded by the MDR1 3435 C>T Gene Polymorphism in Differentiated Thyroid Cancers

BACKGROUND P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter which plays an important role in pharmacokinetics. The current preliminary study was designed to determine associations between a germ-line polymorphism in the MDR1 gene with differentiated thyroid carcinoma (DTC). MATERIALS AND METHODS In the current case-control study, 60 differentiated thyroid cancers (DTC)- 45 papillary TC (PTC), 9 follicular TC(FTC) and 6 well-differentiated tumors of uncertain malignant potential (WDT-UMP) were examined. Results were compared to a healthy control group (n=58) from the same population. Genomic DNA was extracted from peripheral blood with EDTA and the target gene was genotyped by real-time PCR. RESULTS Carriers of the variant allele of MDR1 exon 26 polymorphism were at 2.8-fold higher risk of DTC than the control group (odds ratio [OR]: 0.3805, 95% confidence interval [Cl]: 0.1597-0.9065 (p> 0.046). CONCLUSIONS Presented results suggest that the MDR1 3435TT genotype might influence risk of development of DTC and that the CC genotype might be linked to a poor prognosis. Large-scale studies are now needed to validate this association.

Combined point mutations in codon 12 and 13 of KRAS oncogene in prostate carcinomas

Prostate cancer is a common malignancy that develops by structural mutation(s) and/or other genetic alterations in specific genes.The G to T transversions in codon 12 and C to T transitions in codon 13 of KRAS proto-oncogene are predominant point mutations that occur in about 20% of different cancers in human. In the current study it was aimed to investigate the prevalence and predictive significance of KRAS mutations in patients with prostate carcinomas. In a total of 30 fresh tumoural tissue specimens were investigated in patients with prostate carcinoma. All tumoural specimens were histo-pathologically diagnosed and genotyped for codon 12, 13 KRAS point mutations by reverse hybridisation and direct sequencing methods. KRAS mutations were found in 12 (40%) samples with 29 samples deriving from adenocarcinomas and 1 sample was small cell prostate carcinoma. In 1 (3.44%) sample codon 12 was found to be mutated and in 2 (6.8%) samples codon 13 and in 9 (31%) samples combined codon 12 and 13 were found to be mutated particularly in higher grade of tumoural tissues. Our study, based on representative collection of human prostate tumours, indicates that combined mutations in codons 12 and 13 KRAS are relatively infrequent and most commonly occur in prostate carcinomas.

Combined Effect of Factor V Leiden, MTHFR, and Angiotensin-Converting Enzyme (Insertion/Deletion) Gene Mutations in Hypertensive Adult Individuals: A Population-Based Study from Sivas and Canakkale, Turkey

BACKGROUND Hypertension is one of the leading causes of mortality and morbidity in the world, which is influenced by environmental and genetic factors. The methylenetetrahydrofolate reductase (MTHFR) and angiotensin-converting enzymes (ACE) are possible candidate genes that may influence both body fatness and blood pressure (BP). The purpose of this study was to examine the carriage of gene combinations of the ACE (insertion/deletion [I/D]), MTHFR 677T and 1298C, and lipid profiles in patients with essential hypertension (EH) in Turkey. METHODS A total of 150 adult individuals (50 hypertensive, 50 first-degree relatives, and 50 healthy controls) from Sivas/Turkey with the same age and gender were assessed for body composition, lipid profiles, resting BP, and gene profiles. Additionally, 149 individuals (99 hypertensive, 50 controls) from Canakkale/Turkey had been investigated for ACE I/D polymorphism. Peripheral blood samples were genotyped using strip assay reverse-hybridization multiplex polymerase chain reaction tests for target genes. RESULTS Heterozygous mutation in FV Leiden was found to be higher in the hypertensive and first-degree relatives when compared with the control group (p<0.05). Homozygous DD alleles of the ACE gene were also higher than the ACE I/D and control groups (p<0.05). The high rates of cholesterol and low-density lipoprotein and low rates of high-density lipoprotein were found in patients with EH when compared with the control. CONCLUSION Results show that ACE with DD alleles and mutated alleles of FV Leiden and MTHFR genes were significantly different between genotypes and have a combined effect on EH in Turkish population. Further studies are needed to investigate the genetics of obesity, EH, and BP phenotypes in the current adult population.

Single-nucleotide polymorphism in Turkish patients with adolescent idiopathic scoliosis: Curve progression is not related with MATN-1, LCT C/T-13910, and VDR BsmI

The role of genetics in the etiopathogenesis of adolescent idiopathic scoliosis (AIS) is unclear. In this study, we investigated the relationship between AIS and polymorphisms in MATN‐1, LCT C/T‐13910, and VDR BsmI genes. 53 Turkish adolescents with diagnosed AIS and 54 healthy adult individuals were included in the study. MATN‐1, LCT C/T‐13910, and VDR BsmI gene mutations were analyzed with real‐time PCR. We did not detect a statistically significant difference between AIS and control groups in respect to those three different gene polymorphisms (p < 0.05). We next evaluated the associations of all three SNPs with scoliosis curve severity. There was no significant difference between curve severity and gene polymorphisms (p < 0.05). In terms of gene polymorphisms, AIS patients with a family history of AIS did not significantly differ from AIS patients who did not have history (p < 0.05). AIS might be caused by many different gene mutations, biomechanical mechanisms that have been modified by environmental factors, different biological interactions, modulation of growth, or a synergy of different factors causing abnormal control of growth. However, the existing knowledge is still not enough to explain the etiopathogenesis of AIS.

The critical period of weed control in double-cropped soybean

Double-cropped soybean after winter cereals is the most common soybean production system in the eastern Mediterranean region of Turkey. Weeds are among the main obstacles to double-cropped soybean. A study was conducted in 2002 and 2003 to determine the critical period of weed control (CPWC) for double-cropped soybean. The treatments consisted of either allowing weeds to infest the crop for increasing durations after sowing, or maintaining plots weed-free for increasing durations after sowing. The Gompertz and logistic equations were fitted to relative yields representing the critical weed-free period and the critical time of weed removal, respectively. Johnsongrass (Sorghum halepense), common cocklebur (Xanthium strumarium) and field bindweed (Convolvulus arvensis) were the dominant weeds. For 5% crop loss level, the CPWC was almost all season long, whereas it was from V1 to R6-R7 growth stages for 10% yield loss level. These findings indicate that pre-sowing or pre-emergence control methods should be applied in the region to avoid greater crop losses.

Biological Weed Control

Abstract The biological approach, as an integral part of integrated and sustainable weed control approaches, has an increasing importance and consideration due to increasing environmental and anthropogenic problems. Successful weed control through use of biological agents has a background of more than a couple of centuries. In this chapter, we started with a more classical way of biological approach to introduce arthropods, mainly insects, followed by examples of redistribution of local arthropods. In the bioherbicide section, we have focused on formulated natural products and formulations. Biological weed control faces problems such as inadequacy of finance, some side effects, and conflicting views. However, biological methods are expected to provide more promising weed control practices in the future.