In this study, the most commonly used herbicide, glyphosate, was investigated for its genotoxic effects on the genome of Triticum aestivum. Five different concentrations of the herbicide were used, and alterations to DNA were measured quantitatively based on their RAPD (Randomly Amplified Polymorphic DNA) profiles. The genomic template stability (GTS%) at each concentration was evaluated, and a decrease was observed with increasing glyphosate concentration. Thus the highest concentration was concluded to be the most effective for causing alteration to DNA. Additionally, the coupled restriction enzyme digestion-random amplification (CRED-RA) technique was used to determine an epigenetic mechanism, e.g. DNA methylation. The polymorphic percentages of all concentration were calculated after herbicide applications. When in glyphosate doses compared with control group, all applications of glyphosate observed to consist of methylation. The methylation levels range from 28.3 to 73.9 % (DNA hypermethylation). In conclusion, based on the RAPD and CRED-RA results, glyphosate causes DNA alterations and methylation.

Conditions of environmental stress are known to lead genetic and epigenetic variability in plants. DNA methylation is one of the important epigenetic mechanisms and plays a critical role in epigenetic control of gene expression. Thus, the aim of the study was to investigate the alteration of genome methylation induced by zinc stress by using coupled restriction enzyme digestion-random amplification (CRED-RA) technique in maize (Zea mays L.) seedlings. In addition, to determine the effect of zinc on mitotic activity and phytohormone level, high-pressure liquid chromatography (HPLC) and mitotic index analysis were utilized. According to the results, mitotic index decreased in all concentrations of zinc except for 5 mM dose and chromosome aberrations such as c-mitosis, stickiness, and anaphase bridges were determined. It was also observed that increasing concentrations of zinc caused an increase in methylation patterns and decrease in gibberellic acid (GA), zeatin (ZA), and indole acetic acid (IAA) levels in contrast to abscisic acid (ABA) level. Especially increasing of ABA levels under zinc stress may be a part of the defense system against heavy metal accumulation in plants.

We aimed to determine the genotoxic potential of essential oil (EO) obtained from Nepeta nuda. The chemical content of EO was measured via gas chromatography/mass spectrometry. The most abundant contents were 4aα,7β,7aα-nepetalactone (18.10%), germacrene (15.68%) and elemol (14.38%). For genotoxic effects of EO, Zea mays’ seeds were exposed to four different concentrations of this oil. Inhibition of root and stem growth were observed with an increase in EO concentrations. Randomly amplified polymorphic DNA (RAPD) method was used to determine the genotoxic effects of EO. Some changes occurred in RAPD profiles of germinated EO-treated seeds. Even though total soluble protein quantity vary, the data observed from the protein profiles of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that there was a little differentiation between band profiles of treated samples and control group. We concluded that the basis of interactions between plants, like allelopathy, may be related with genotoxic effects of EO.

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