Plants are masters of epigenetic regulation. All of the major epigenetic
mechanisms known to occur in eukaryotes are used by plants, with the responsible
pathways elaborated to a degree that is unsurpassed in other taxa. DNA methylation
occurs in plant genomes, in patterns that reflect a balance between enzyme activities
that install, maintain, or remove methylation. Histone-modifying enzymes influence
epigenetic states in plants and these enzymes are encoded by comparatively large gene
families, allowing for diversified as well as overlapping functions. RNA-mediated gene
silencing is accomplished using multiple distinct pathways to combat viruses,
orchestrate development, and help organize the genome. The interplay between DNA
methylation, histone modification, and noncoding RNAs provides plants with a
multilayered and robust epigenetic circuitry that has a tangible impact on the control of
plant genes conferring resistance to different biotic and abiotic stresses, either directly
or indirectly. Eventually, plants with the most suitable epigenome may be subject to
selection.
Keywords: Epigenetic control, Epigenetic modifications, Epigenome,
MicroRNAs (miRNAs), Non coding small (sRNA), Plant DNA methylation
changes, Transgenerational epigenetically acquired resistance, Transposable
elements (TEs).