Gibberellin homeostasis and signaling in plant growth, stress adaptation, and crop improvement

Gibberellins (GAs) are diterpenoid phytohormones that regulate seed germination, organ elongation, flowering, and reproductive development, but recent work shows that GA function depends on spatially controlled homeostasis rather than hormone abundance alone. Here, we synthesize advances in GA biosynthesis, transport, and signaling, focusing on the localized production of bioactive GAs, movement of precursors such as GA₁₂, feedback regulation of GA 20-oxidase (GA20ox), GA 3-oxidase (GA3ox), and GA 2-oxidase (GA2ox), and the GIBBERELLIN INSENSITIVE DWARF1 (GID1)-DELLA signaling module. We discuss how DELLA-centered signaling integrates GA responses with auxin, abscisic acid, brassinosteroid, cytokinin, jasmonate, ethylene, and strigolactone pathways to coordinate source–sink relations, thermomorphogenesis, salinity responses, and growth–stress trade-offs. We also examine how classical dwarfing alleles and CRISPR/Cas-based genome editing of GA metabolic and signaling components are used to improve crop architecture while minimizing pleiotropic effects. Finally, we highlight unresolved questions involving tissue-level GA dynamics, non-canonical signaling in cereals, and environment-specific tuning of GA responses. By linking molecular mechanisms with stress adaptation and crop design, we present GA biology as a practical framework for improving plant performance in changing environments.