Esra Arslan

Determination of genomic instability and DNA methylation effects of Cr on maize (Zea mays L.) using RAPD and CRED-RA analysis

In this research, we aimed to evaluate DNA damage levels, DNA methylation, protein and phytohormone levels changes in corn (Zea mays L.) seedlings exposed to chromium nitrate (Cr). The results showed that the used all chromium doses caused a decreasing mitotic index, genomic template stability and soluble protein levels and increasing in RAPDs profile changes (DNA damage) and DNA hypermethylation. In additional, in the high-pressure liquid chromatography analyses, it was also observed that Cr contamination caused a decreasing in the growth-promoting hormones including gibberellic acid (GA), zeatin (ZA) and indole acetic acid (IAA) levels, in contrast to abscisic acid (ABA) level. The results of this experiment have clearly shown that Cr has epigenetic effect as well as genotoxic effect. Some of phytohormones decreasing (GA, ZA and IAA) and especially increasing of ABA levels under Cr stress may be a part of the defense system against the stress.

Determination of genotoxic effects of boron and zinc on Zea mays using protein and random amplification of polymorphic DNA analyses

In this research, we aimed to determine genotoxic effects of boron (B) and zinc (Zn) on Zea mays by using total soluble protein content and random amplification of polymorphic DNA (RAPD) analyses. For the RAPD analysis, 16 RAPD primers were found to produce unique polymorphic band profiles on treated maize seedlings. With increased Zn and B concentrations, increased polymorphism rate was observed, while genomic template stability and total soluble protein content decreased. The treatment with Zn was more effective than that of B groups on the levels of total proteins. The obtained results from this study revealed that the total soluble protein levels and RAPD profiles were performed as endpoints of genotoxicity and these analyses can offer useful biomarker assays for the evaluation of genotoxic effects on Zn and B polluted plants.

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.

Cytogenetic and epigenetic alterations by cobalt and nickel on Zea mays L

Changes in DNA methylation in Zea mays plantlets in response to cobalt and nickel (5, 10, 20, and 40 mmol L−1) evaluated by the coupled restriction enzyme digestion-random amplification technique revealed dose-related increases in hypermethylation. The effects on mitotic index and phytohormone levels were also determined. Co and Ni caused a decrease in mitotic index and an attenuation in the growth-promoting hormones gibberellic acid, zeatin, and indole acetic acid, while abscisic acid levels rose. These findings have shown that the increase in abscisic acid levels and DNA methylation depend on the concentrations of Co and Ni.

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.

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).