Abstract:Hormone gibberellins (GAs) play an essential role in many aspects of plant growth and development, such as seed germination, stem elongation and flower development. In recent years, exciting progress has been made in identifying many genes involved in gibberellin biosynthesis and the gibberellin signal transduction pathway. This has helped us to understand these pathways and their regulation. The e
xpression of gibberellin biosynthesis genes are regulated by several endogenous and environmental factors , including developmental stage, hormone status and light. The basal state of GA signaling is likely to be repressive and the GA signal seems to activate the pathway by de_repression to allow GA_stimulated growth and development.