Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: September 1, 2009
Publication Date: December 1, 2009
Citation: Horvath, D.P. 2009. Bud Dormancy and Growth. In: Pua and Davey, Editors. Plant Developmental Biology - Biotechnological Perspectives. Vol. 1. Springer-Verlag Berlin Heidelberg. Chapter 4, pp. 53-70. Interpretive Summary: This book chapter reviews various aspects of bud dormancy. Environmental and molecular signals regulate various types of dormancy including paradormancy (also known as apical dominance or correlative inhibition), endodormancy (also known as innate dormancy or seasonal dormancy), and ecodormancy (also known as conditional or environmental dormancy). The genes and signals involved in all three dormancy states are presented, as are current hypotheses on how these signals alter key physiological processes needed for dormancy induction and release.
Technical Abstract: Nearly all land plants produce ancillary meristems in the form of axillary or adventitious buds in addition to the shoot apical meristem. Outgrowth of these buds has a significant impact on plant architecture and the ability of plants to compete with neighboring plants, as well as to respond to and survive environmental hardships. Consequently, it is not surprising that plants have developed complex mechanisms for regulating dormancy and growth of apical, axillary, and adventitious buds. Different mechanisms impact bud dormancy as defined by the source of the signals preventing bud growth. Paradormant buds are kept from growing by signals generated in other parts of the plants. Growth of endodormant buds is prevented by signals generated within the bud itself. Extreme environmental conditions that limit growth, but which are not immediately fatal, can induce an ecodormant state within buds. Various plant hormones play an integral part in the development and maintenance of all forms of dormancy. Additionally, environmental conditions can modify the expression of regulatory genes that impact bud growth, physiology, and development to bring about specific dormancy states. This chapter discusses the environmental and developmental signals known to regulate bud growth and dormancy, and presents current hypotheses concerning the molecular mechanisms that regulate dormancy transitions.