Epigenetics is a relatively new science of the broader field of genetics and refers to heritable changes in gene expression or phenotype. These epigenetic changes do not involve changes in the actual DNA sequence itself but rather, modifications in histones that comprise the chromatin and DNA methylation as well as an ever expanding array of other epigenetic processes. Innovative technology has driven the field of epigenetics as well as the development of novel model organisms of epigenetics. Metabolic processes impact epigenetics and epigenetic modifications are important in many functions that affect a vast number of organisms. Epigenetics has influenced evolution and epigenetic epidemiology has demonstrated the intricate role between epigenetics and the environment. Lastly, a number of human diseases such as cancer, brain disorders and metabolic syndromes have been associated with aberrations in epigenetic processes that now open a new area of advances in epigenetic therapy.
Plants are sessile organisms that must constantly adjust to their environment. In contrast to animals, plant development mainly occurs postembryonically and is characterized by continuous growth and extensive phenotypic plasticity. Chromatin-level regulation of transcriptional patterns plays a central role in the ability of plants to adapt to internal and external cues.