Vernalization and the initiation of flowering

We propose that Arabidopsis has a vernalization (low temperature) dependent and a vernalization-independent induction pathway for the initiation of inflorescence development in the shoot apex. Our data suggest that the vernalization-dependent pathway is normally blocked by methylation of the promoter of a gene critical for floral induction and that the low temperature treatment activates the pathway by reducing the methylation status of the gene(s) Kaurenoic acid hydroxylase (KAH), a gene early in the GA biosynthesis pathway is s suggested as the methylation controlled gene. Vernalization results in expression of KAH in the shoot apex and the synthesis of the bioactive Gas which promote flowering. We propose that the vernalization independent pathway involves the supply and transport of carbohydrate to the shoot apex.