Mahmut Sinan Taspinar

Determination of Variations of Some Enzymes in Orchardgrass ( Dactylis glomerata L.) Ecotypes

In the present study, wild orchardgrass ( Dactylis glomerata L.) collected from four different locations (Oltu, Olur, Uzundere and Uluba < ) of Erzurum (Turkey) were used to investigate various electrophoretic analyses within and between four ecotypes based on peroxidase (PRX), polyphenol oxidase (PPO) and malate dehydrogenase (MDH) enzymes. Four natural populations of Dactylis glomerata showed genetic variability within and among ecotypes based on similarities and polymorphism of isoenzyme bands. In addition, a dendogram analysis was made according to band patterns indicating that ecotypes could be grouped showing characteristics in relation to each other, notably Oltu-Uluba < and Olur-Uzundere. However, the degree of relationship of Oltu-Uluba < (6 units) was higher than Olur-Uzundere (12 units).

Effects of As2O3 on DNA methylation, genomic instability, and LTR retrotransposon polymorphism in Zea mays.

Arsenic is a well-known toxic substance on the living organisms. However, limited efforts have been made to study its DNA methylation, genomic instability, and long terminal repeat (LTR) retrotransposon polymorphism causing properties in different crops. In the present study, effects of As2O3 (arsenic trioxide) on LTR retrotransposon polymorphism and DNA methylation as well as DNA damage in Zea mays seedlings were investigated. The results showed that all of arsenic doses caused a decreasing genomic template stability (GTS) and an increasing Random Amplified Polymorphic DNAs (RAPDs) profile changes (DNA damage). In addition, increasing DNA methylation and LTR retrotransposon polymorphism characterized a model to explain the epigenetically changes in the gene expression were also found. The results of this experiment have clearly shown that arsenic has epigenetic effect as well as its genotoxic effect. Especially, the increasing of polymorphism of some LTR retrotransposon under arsenic stress may be a part of the defense system against the stress.

Protective role of humic acids against dicamba-induced genotoxicity and DNA methylation in Phaseolus vulgaris L.

Dicamba is one of herbicides used widely in agriculture today. The wide use of dicamba in agriculture represents a potential danger to the ecosystems and the environment. Thus, the present study is aimed to investigate the DNA damage levels and the DNA methylation changes in Phaseolus vulgaris subjected to whether dicamba and humic acids (HAs) have any protective effect on these changes. Randomly Amplified Polymorphic DNAs (RAPDs) and Coupled Restriction Enzyme Digestion-Random Amplification (CRED-RAs) were used to determinate the DNA damage levels and the changes in the pattern of DNA methylation. The results showed that dicamba (0.2, 0.4 and 0.6 ppm) caused RAPDs profile changes (DNA damage) as increasing, genomic template stability (GTS) as decreasing and DNA hypomethylation. However, these effects of dicamba seen at higher levels decreased after treatment with five different concentrations (2, 4, 6, 8 and10%) of HAs. The results of this experiment have clearly shown that HAs could be used effectively to protect bean seedlings from the destructive effects of dicamba.

Analyses of somaclonal variation in endosperm-supported mature embryo culture of rye (Secale cereale L.)

ABSTRACT Genetic variations, and especially somaclonal variations, are undesirable in genetic transformation. In this study, random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) markers were used for detection of the variation in calli that were obtained from endosperm-supported mature embryo of rye on Murashige and Skoog (MS) medium containing different auxins (2,4-D, dicamba and picloram) at a range of different concentrations (2, 4, 6, 8, 10 and 12 mg/L). High level of auxins caused a reduction in the genomic template stability (GTS) value. While the highest GTS was observed in the calli maintained on MS medium with 2 mg/L dicamba (98.4%), the calli maintained on MS medium with 12 mg/L picloram were found to show the least GTS (81.7%) when RAPD patterns were analysed. Epigenetic changes were more frequent and variable than genetic changes when compared to RAPD and CRED-RA results. DNA hypermethylation was observed at higher concentrations of 2,4-D and picloram, whereas DNA hypomethylation was observed in dicamba. These results indicate that RAPD and CRED-RA techniques can be used for detection of somaclonal variation in in vitro cultures, which is a fundamental step in plant genetic transformation.

Static magnetic field induced epigenetic changes in wheat callus.

Deoxyribonucleic acid (DNA) is always damaged by endogenous and exogenous factors. Magnetic field (MF) is one of these exogenous factors. When repair mechanisms are not sufficient, mainly because of imbalance in damage or mistakes in repair mechanisms, methylation of DNA results in polymorphism-related abnormalities. In this study, low intensity static magnetic field-induced DNA damage and methylation in wheat calli were investigated by using Random Amplified Polymorphic DNA and Coupled Restriction Enzyme Digestion-Random Amplification techniques. Calli were derived from mature embryos of wheat. Both 7- and 14-day-old wheat calli were exposed to 7 mT (millitesla) static MF for 24, 48, 72, 96, or 120 h of incubation period. The highest change in polymorphism rate was obtained in calli exposed to 7 mT MF for 120 h in both 7- and 14-day-old calli. Increase in MF duration caused DNA hypermethylation in both 7- and 14-day-old calli. Polymorphism and DNA methylation ratio were higher in 7-day-old calli. The highest methylation level with a value of 25.1% was found in 7-day-old calli exposed to MF for 120 h. Results suggested that low intensity static magnetic field may trigger genomic instability and DNA methylation. Bioelectromagnetics. 37:504-511, 2016.

Dicamba causes genomic instability in Phaseolus vulgaris seedlings

The herbicide 3,6-dichloro-2-methoxybenzoic acid (dicamba) is principally used widely agriculture today. The widely use of dicamba in agriculture may represent a potential toxic risks to some crops. Thus, the present study aimed to evaluate the genotoxic effects of dicamba by using randomly amplified polymorphic DNA (RAPD) in Phaseolus vulgaris seedlings. The results showed that persistent DNA damage and decreased genomic template stability (GTS) induced by dicamba (0,2, 0,4 and 0,6 ppm).

The effects of mercury on genomic stability in corn

It is a true that heavy metals have an effect plant species like affecting all of the living organisms into the existing environments. Heavy metals have hazardous effects on living organism. Several plant species have been used bio-indicators in order to determine the effects on genetic toxicity of heavy metal pollution so far. The aim of this paper detects the effects of Mercury chloride (HgCl2) were investigated on genetic stability/or DNA damage in maize seedlings. The results showed that all mercury doses used cause a decrease in the genomic template stability, while they cause an increase in the RAPDs profile changes (DNA damage).