Probable E3 ubiquitin-protein ligase. Has no effect on the stability of the DELLA proteins. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein degradation; proteasomal ubiquitin-dependent pathway. Interacts with the DELLA proteins GAI, RGA, RGL1, RGL2 and RGL3. Down-regulated by pathogen, salicylic acid and 1-aminocyclopropane-1-carboxylic acid (ACC). Up-regulated by salt, gibberellic acid and methyl jasmonate. The RING-type zinc finger domain mediates binding to an E2 ubiquitin-conjugating enzyme. No visible phenotype. Decreased resistance to B.cinerea and increased cell death upon pathogen infection. Boi, brg1, brg2 and brg3 quadruple mutant shows a higher GA signaling resulting in a higher seed germination in the presence of paclobutrazol, precocious juvenile-to-adult phase transition and early flowering.