Arabidopsis thaliana is an annual flowering plant found in the mustard family. This research paper is focused on determining epigenetic methylation in Arabidopsis thaliana. (Experiment) A population of 50 ddm1-2-derived Arabidopsis epiRILs will be planted under moderately and favorable saline conditions to aid this study. The population will then be assessed to determine the number of morphology-related and plant growth characteristics under both conditions. (Hypothesis) The study then hypothesizes that experimentally triggered hypomethylation of chromosomes can make Arabidopsis thaliana more plastic in its response and more sensitive to environmental variations. (Expected results) Epigenetics influences Arabidopsis thaliana phenotypic plasticity since epigenetic changes, as opposed to DNA sequence variation, are more likely to be irreversible.

Epigenetic is a field of study that relates to the study of heritable modifications in gene appearance, which does not entail changes in the original DNA sequence that, in turn, influences how the cells translate the genes. Likewise, it is basically the change in phenotype without involving a change in genotype. An epigenetic change is a natural and regular phenomenon but it can also be affected by a number of factors that include but not limited to disease status, age and environment or lifestyle. An epigenetic change is evident in the manner in which cells terminally dissociates to end up as liver cells, skin cells, and brain cells, for example. Additionally, an epigenetic modification can also lead to the occurrences of several diseases, for example, cancer and other inherited diseases. Studies on epigenetics have shown that histone modification, non-coding RNA (ncRNA) and DNA methylation and their associated gene silencing are responsible for initiating and sustaining epigenetic modifications.

Ernst Hadorn and Conrad H. Waddington, during the mid-twentieth century, coined the term epigenetics when they were determined to study developmental biology and combining genetics. Waddington specifically coined the term epigenetics, in 1942; a term he used to refer to the influence of genetic processes on human development. Later on, in the 1990s, there was an increased interest in studying genetic assimilation. This also led to the elucidation of the molecular basis of Conrad Waddington’s study where he established that environmental stress triggered genetic assimilation of some phenotypic traits in Drosophila fruit flies. In the modern epigenetic studies, DNA methylation is the most studied field among other forms of modifications, which include non-coding RNA mechanism, histone modifications and chromatin remodeling.

A number of studies on the function of methylation in gene manifestation believed that methylation played a key function in suppressing gene expression, by occupying the promoters where activating transcription factors were believed to bind. Up to date, the key function of methylation in gene manifestation has not been discovered, however, it is apparent that sufficient DNA methylation is a necessity for embryonic development and cell differentiation. Likewise, research observations have also indicated that methylation plays a key role in mediating gene expression. One of the studies showed that methylation occurring around gene promoters varies significantly depending on the type of a given cell. It has also been noted that methylation completeness and levels of a specific promoter are similar in a given person, however, there are discrete differences in specific and overall methylation levels between cancer cells and normal cells, and also between different tissue types.

Promoters are DNA sequences that are assigned to the 5’ region that is adjacent to the transcriptional start site. The process begins with the polymerization of RNA to produce accessory proteins that bind to the promoter sites to initiate the production of a mRNA transcription. Interactions of the proteins at the promoter sites is what causes gene repression or activation. For instance, tissue-specific expression of FWA is regulated by the DNA methylation on the FWA promoter.