Abstract
Extensive studies using the model plant organism Arabidopsis suggested that many developmental processes in plants occur via gene regulation achieved through epigenetic mechanisms such as histone modification and chromatin remodeling. The transition to flowering, prerequisite for reproductive success, has been intensively studied and provided a window to understand epigenetic mechanisms in plants. The potent flowering repressor, FLOWERING LOCUS C (FLC), is epigenetically silenced by vernalization, a long-term cold exposure, conferring upon plants the competence to flower. Conversely, a strong activator of flowering, FT, is epigenetically suppressed during the vegetative growth phase, but is expressed in tissue-specific pattern upon exposure to inductive photoperiod. Here we describe epigenetic changes associated with repressing/activating FLC and FT expression. More generally, we consider recent genome-wide studies of histone modification, DNA methylation and the role of TERMINAL FLOWER 2 (TFL2) / LIKE-HETEROCHROMATIN PROTEIN 1 (LHP1) ; such studies serve to enhance global understanding of epigenetic mechanisms in plants, and illustrate some differences among epigenetic mechanisms used by plants and animals.
