Molecular GA pathways as conserved integrators for adaptive responses

Gibberellins (GAs), which form a large family of phytohormones involved in almost every step of plant life and development, were discovered almost a century ago. The molecular characterization of GA metabolism and signalling mechanisms now provides explanations for the multiple crosstalk and the integration of external signals required for plants to adapt their development and growth to environmental conditions. In this review, we present the molecular elements of GA metabolism and signalling pathways, with emphasis on the key role of the GA/GID1/DELLA complex as a conserved developmental integrator. Further, we discuss how the GA signalling pathway, together with feedback regulation on GA metabolism, contributes to the integration of endogenous and exogenous signals to provide an adaptive output.