Genetics and Biochemistry of Seed Flavonoids Lo¨ ıc Lepiniec, Isabelle Debeaujon, Jean-Marc Routaboul, Antoine Baudry, Lucille Pourcel, Nathalie Nesi, and Michel Caboche Seed Biology, Institut Jean-Pierre Bourgin (IJPB), INRA, 78026 Versailles, France; email: lepiniec@versailles.inra.fr Annu. Rev. Plant Biol. 2006. 57:405–30 The Annual Review of Plant Biology is online at plant.annualreviews.org doi: 10.1146/ annurev.arplant.57.032905.105252 Copyright c  2006 by Annual Reviews. All rights reserved First published online as a Review in Advance on February 1, 2006 1543-5008/06/ 0602-0405$20.00 Key Words bHLH, condensed tannins, flavonols, MYB, proanthocyanidins, WDR Abstract Flavonoids are secondary metabolites that accumulate in most plant seeds and are involved in physiological functions such as dormancy or viability. This review presents a current view of the genetic and biochemical control of flavonoid metabolism during seed develop- ment. It focuses mainly on proanthocyanidin accumulation in Ara- bidopsis, with comparisons to other related metabolic and regulatory pathways. These intricate networks and their fine-tuned regulation, once they are determined, should contribute to a better understand- ing of seed coat development and the control of PA and flavonol metabolism. In addition, flavonoids provide an interesting model to study various biological processes and metabolic and regulatory networks. 405 Annu. Rev. Plant. Biol. 2006.57:405-430. Downloaded from arjournals.annualreviews.org by CNRS-multi-site on 05/04/06. For personal use only.