Theoretical and applied epigenetics in plants

Abstract

Artificial regulation of gene expression through RNA-directed DNA méthylation (RdDM)-mediated epigenome editing is one the most important and attractive next-generation technologies for plant trait improvement, often called "new plant breeding techniques" (NPBTs). RdDM can induce transcriptional gene silencing (TGS) of a target gene via modification of the cytosine methylation levels of its promoter region; thus, RdDM is useful as a method for suppression of gene expression without changing the genomic DNA sequence. Likewise, several types of strict epigenetic regulation occur at both the DNA and chromatin levels under normal growth conditions in plants. Recent studies have revealed genome-wide and organ-specific landscapes of epigenetic modifications and their close relationship to plant growth regulation. Therefore, understanding recent findings concerning epigenetic regulation in plants is very important to the future application of epigenome editing in plant breeding. In this chapter, we illustrate several aspects of theoretical and applied epigenetics in plants through discussion of recent studies.