Figure 3.

Proposed pathways to flowering in Arabidopsis. Some of the genes in the pathways (11, 21, 22) are indicated, but no order of function is intended from the order in which the genes are listed. There may be some functional interaction and/or overlap of these pathways that is not indicated in this simplified model. The step in the vernalization pathway that is blocked, in the absence of a cold treatment, is indicated by the box. The block represented by the shaded part of the box can be alleviated by demethylation, but the unshaded portion is only alleviated by cold. The methylation block may lie within the vernalization pathway and/or in a parallel pathway, as indicated.