Cuiling Huang, Zhe Chai, Hengyan Zhang, Jinlan Fang and Muqing Zhang
Guangxi Key Laboratory for Sugarcane Biology & State Key Laboratory for Conservation and Utilization of Subtropical Agri-Biological Resources, Guangxi University, Nanning, 530005, China; zmuqing@163.com
Sugarcane (Saccharum hybrids) is the leading sugar crop, with stem elongation crucial for yield. We identified ScGID2, an F-box protein from cultivar ROC22, with broad expression in stems and leaves. Its expression was modulated by gibberellin (GA) and paclobutrazol (PAC), indicating a role in GA homeostasis. Functional analyses showed ScGID2 forms a GA-dependent complex with ScGID1 (GA receptor) and ScGAI (DELLA protein), independent of its F-box domain. ScASK1 (SKP1-like protein) stabilized the ScGID2-ScGAI interaction. The F-box domain bound ScASK1, while the C-terminal facilitated complex assembly. These findings establish ScGID2 as a key GA signaling regulator in sugarcane, mediating growth and stem elongation.