Epigenetics

Scope

Epigenetics may be defined to include mechanisms that involve heritable changes other than those in DNA nucleotide sequence.

Genetic improvement of crops underpinned massive increases in yield and food production over the past century. This was based on breeding programs carried out within a framework and understanding of Mendelian and quantitative genetics. However, despite whole-genome DNA sequencing and precision genetics, the rates of increase have now slowed.

Sequencing of the human genome did not provide the anticipated answers about the causative mutations for common diseases and cancers. However, over the past decade understanding the role for epigenetic modifications has advanced rapidly, and revealed the complex interactions underlying these phenotypes. The study and appreciation of epigenetics has thus rapidly become mainstream in human and animal genetics.

Although it is now apparent from many studies that epigenetic regulation, mediated through marks that affect chromatin structure, play a major role in the control of development and response of plants to environment, there has not yet been a corresponding paradigm shift, particularly in crop breeding and agronomy. However, an increasing range of agronomic traits are being shown to be affected to some extent by stably inherited epigenetic modifications. The molecular basis of the innate plasticity that plants possess in terms of phenotype and development, is gradually being unravelled.

Many of the fundamental molecular insights into regulation of epigenetic processes have originated in plants (transposons, miRNA), but relatively little in relation to crop phenotype and quality. Compared with animal genomes, there are important differences in the prevalence and pattern of DNA methylation marks in plant genomes, where epiallelic variation in methylation is also often stably inherited through meiosis.

Current Research

  • Epigenetic marks in the Brassica genome
  • Epigenetic intervention as a crop improvement strategy

Links

Online and news

Publications

Theses supervised by Graham King

Usher S (2009) Nucleosome positioning in Arabidopsis. University of Warwick.

Amoah A (2010) The role of DNA methylation in crop phenotype plasticity. University of Reading.

Posters

Higgins J, Corpas M, Chapman N, King GJ, Seymour GB, Swarbreck D. (2012). Effect of a wild species introgression on genome methylation in Tomato. UK Next Gen Sequencing Meeting 2012, Nottingham, UK