Probable transcriptional regulator that acts as a repressor of the gibberellin (GA) signaling pathway. Probably acts by participating in large multiprotein complexes that repress transcription of GA-inducible genes. Upon GA application, it is degraded by the proteasome, allowing the GA signaling pathway. Acts as a negative regulator of GAMYB gene expression. Apparently restricted to regions where growth is occurring in the leaf blade. Localizes almost exclusively to the basal elongation zone (EZ) for the elongating blades of L1, L2 and L3. More detailed fractionation of the L3 blade shows that in cv. Himalaya, it is preferentially localized to the basal third of the EZ, but its presence can still be detected toward the end of the EZ (at protein level). The DELLA motif is required for its GA-induced degradation. Phosphorylated. Ubiquitinated (Probable). Upon GA application it is ubiquitinated, leading to its subsequent degradation. Belongs to the GRAS family. DELLA subfamily.