Common mechanisms regulate flowering and dormancy

In 1960, Chouard hypothesized that there might be a connection between vernalization (facilitation of floral competence) and release from endodormancy. In 2003 we reiterated this hypothesis and suggested potential mechanisms involving chromatin remodeling. Since then, there have been several papers from various laboratories working on several different perennial species that suggest common signaling components regulate flowering and the growth cessation that must precede endodormancy induction. This work has directly implicated FT, CENL1, and MADS-box transcription factor genes similar to SVP and/or AGL24 in growth cessation and endodormancy development. Numerous studies in other model systems have demonstrated the function and regulation of similar genes in floral regulation. Combined, these studies allow the development of a paradigm for future investigations designed to understand the nature and function of the regulatory mechanisms that control induction and release of endodormancy in perennial plants. Dicots, monocots, and gymnosperms have similar floral regulatory genes, suggesting that general regulation of flowering is highly conserved among perennial species. Likewise, reports of differential expression of particular MADS-box genes and putative FT orthologues during endodormancy transitions across multiple plant species suggest a conserved role for these genes in responses to endodormancy induction and maintenance. The limited but tantalizing linkage between floral regulatory machinery and seasonal growth cessation and bud set through regulation of FT and other FT-like genes suggest a general model for endodormancy regulation.