Vernalization and flowering time.

Vernalization is the process by which flowering is promoted by prolonged exposure to the cold of a typical winter. In certain plant species, the role of vernalization is to suppress the expression of genes that encode repressors of flowering. In Arabidopsis, this suppression is an epigenetic phenomenon in the sense that it is mitotically stable in the spring after the inducing signal, cold, is no longer perceived. This epigenetic silencing results from the modification of the chromatin of flowering repressors.