THE NEED FOR WINTER IN THE SWITCH TO FLOWERING

• Published in: Annual review of genetics Vol. 37; no. 1; pp. 371 - 392
• Main Authors: Henderson, Ian R, Shindo, Chikako, Dean, Caroline
• Format: Journal Article
• Language: English
• Published: Palo Alto, CA 94303-0139 Annual Reviews 01.01.2003; 4139 El Camino Way, P.O. Box 10139 Annual Reviews, Inc; USA
• Subjects: Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis Proteins - physiology; Arabidopsis thaliana; cold response; Cold Temperature; Crops, Agricultural - genetics; Crops, Agricultural - growth & development; epigenetics; Evolution; floral transition; Flowering Tops - growth & development; flowering-time genetics; Flowers & plants; FRI gene; Genomics; MADS Domain Proteins - physiology; Plant reproduction; Plant species; Temperature effects; vernalization; Winter
• ISSN: 0066-4197; 1545-2948
• DOI: 10.1146/annurev.genet.37.110801.142640

Vernalization is the process whereby the floral transition is promoted through exposure of plants to long periods of cold temperature or winter. A requirement for vernalization aligns flowering with the seasons to ensure that their reproductive phase occurs in favorable conditions. The mitotic stability of vernalization, suggestive of an epigenetic mechanism, has intrigued researchers for many years. Genetic analysis of the vernalization requirement in Arabidopsis has identified key floral repressor genes, FRI and FLC . The action of these floral repressors is antagonized by vernalization and the activity of a set of genes grouped into the autonomous floral pathway. Analysis of the vernalization pathway has defined a series of epigenetic regulators crucial for "cellular-memory" of the cold signal, whereas the autonomous pathway appears to function in part through posttranscriptional mechanisms. The mechanism of the vernalization requirement, which is now being explored in a range of plant species, should uncover the evolutionary origins of this key agronomic trait.