Beyond proteolysis: the GA–GID1–DELLA module as a transcriptional control hub in plants

Abstract

Gibberellins (GAs) promote growth and developmental transitions throughout the plant life cycle. A hallmark of GA action is the control of DELLA proteins, master repressors of GA responses. In the canonical pathway, bioactive GA binds the soluble receptor GID1, enabling formation of a GA–GID1–DELLA complex that recruits SCF-type E3 ubiquitin ligases (e.g., SLY1/SNE (SNEEZY; also called SLY2) in Arabidopsis and GID2 in rice) and triggers ubiquitination and 26S proteasome-mediated DELLA degradation (McGinnis et al. 2003; Dill et al. 2004; Gomi et al. 2004; Ariizumi et al. 2011). However, recent work shows that GA can neutralize DELLA output beyond simple proteolysis. Structural analyses reveal proteolysis-independent suppression of DELLA by GA–GID1 binding (Ariizumi et al. 2008; Dahal et al. 2025), chromatin studies show that phosphorylation can activate DELLA by promoting histone H2A binding at chromatin, and nutrient starvation studies identify ATG8-dependent autophagic DELLA degradation during dark skotomorphogenesis. Together, these findings support a hub model in which DELLA output depends on abundance, conformation, post-translational modifications, interaction partners, and chromatin engagement. We highlight how this expanded view of the GA–DELLA module informs precision strategies for crop improvement that tune growth–stress trade-offs with reduced pleiotropy.