Comparison of the DNA Methylation and Expression Changes on Some Cadmium-induced Genes in Bread Wheat Exposed to Cadmium (Cd) Accumulation in the Soil

Abstract Factors such as chemical fertilizers used in recent years, incorrect irrigation techniques, changing climatic conditions increase the accumulation of cadmium (Cd) heavy metal in the soil. In study, it was aimed to determine the expression levels of stress-related genes in the plant and the methylation levels for the first time by Real-Time PCR-based quantitative DNA methylation analysis (qAMP) after Cd stress applied at different concentrations to bread wheat (Triticum aestivum L.), which is an important agricultural product. The development of wheat plants exposed to Cd stress at 0,100, 250, 500 µM doses was achieved and DNA and RNA isolations were performed from these plants. While the gene expression analyze was performed with the cDNAs produced by designing primers specific to the selected gene regions, the DNA methylation ratio were determined by applying the restriction enzyme-based qAMP technique. The obtained results were compared with gene expression analysis. Gene expression levels and DNA methylation percentages of UGT-3, LTP-4 and PIP-1 genes were determined under CdCl2 stress. The percentage of methylation in the UGT-3, LTP-4 and PIP-1 genes was determined at the highest concentration of 250 µM in both the shoot and root. The expression level of the UGT-3 gene gave the highest rate at 250 µM dose in the shoot, while the overexpression of the LTP-4 gene was observed at 250 µM concentration in the root. The changes in methylation rates of UGT-3, LTP-4 and PIP-1 genes were investigated for the first time with qAMP in plants. A significant correlation was observed between the expression levels of genes and their methylation status.