Fig. 1.

A simplified illustration of GA metabolism and signaling pathways in rice. GA biosynthesis starts from GGDP in the plastid and a portion of it is catabolized to inactive forms. Bioactive GAs are perceived by the soluble GA receptor GID1. DELLA protein acts as a negative regulator of the GA responses. In the GA signaling pathway, GA causes the destruction of DELLAs via the 26S proteasome machinery, resulting in GA responses. CDP, ent-copalyl diphosphate; CPS, ent-copalyl diphosphate synthase; GA2ox, GA2 oxidase; GA3ox, GA3 oxidase; GA20ox, GA20 oxidase; GGDP, geranylgeranyl diphosphate; KAO, ent-kaurenoic acid oxidase; KO, ent-kaurene oxidase; KS, ent-kaurene synthase; Ub, ubiquitin.