Application of Higher Concentration of Zn Influences DNA Methylation in Plant Genome

Gene expression in eukaryotes involves the complex interaction among transcription factors and chromatin proteins. Epigenetic mechanisms, such as histone modifications and DNA methylation play a substantial role in the regulation of transcription, which can either, trigger the activation, or repression of genes. It has been observed that the epigenetic changes in DNA are also influenced by the abiotic and biotic stresses such as cold, drought and increase or decrease of minerals and metal concentrations and disease and pest infestation. Our long term goa is to identify epigenomic components of crop plant genome involved in uptake and translocation of health related minerals. In this study, our objective was to investigate the influence of human health related micronutrient stress such as higher concentration of Zn in epiegentic changes (DNA methylation) of plant genome. We conducted replicated trials of three wheat varieties including controls and applied higher concentration of Zn (100mgL^-1) to all varieties from germinatiion to harvesting. At leaf senescence, DNA was extracted from stem, leaf, and head. Methylation Specific Quantitative PCR (MS qPCR) analyses were performed using methylation specific primers designed from metal transporter gene sequences. Our results suggested a significantly higher degree of DNA methylation in plant genome due to higher Zn concentration compared to control (untreated) however degrees of methylation varied from tissues to tissue. We are conducting similar experiments in common bean including six common bean varieties and the finding of this study will help in identifying mineral concentration related epigenetic component in common bean genome.