Gibberellin (GA) signaling is widely regarded as a canonical hormone-controlled growth pathway, yet accumulating evidence suggests that it emerged through stepwise evolutionary assembly rather than as a pre-formed regulatory system. Here, we revisit the origin and diversification of the GA pathway from an evolutionary perspective. DELLA-mediated growth repression arose during early land plant evolution and was later integrated into a hormone-responsive framework following the establishment of GA biosynthesis and perception. The emergence of the receptor GID1 completed the core GA-GID1-DELLA module, enabling dynamic hormonal control of plant growth. Subsequent diversification of this module underpinned key agricultural innovations, including the semi-dwarf traits of the Green Revolution. However, manipulation of GA signaling also exposed trade-offs, particularly between reduced plant height and nitrogen use efficiency (NUE). Recent advances reveal additional regulatory nodes linking GA signaling to metabolic and stress-responsive networks, highlighting the importance of precise hormonal fine-tuning. Looking forward, we propose that integrating comparative genomics, structural biology, protein language models, and artificial intelligence may enable rational rewiring of GA signaling, providing a blueprint for engineering climate-resilient and resource-efficient crops.
Fan et al. (Sat,) studied this question.