Fig. 2

Terpenoid pathway for biosynthesis of gibberellins, abscisic acid, phytol, and steroids, and path for degradation of abscisic acid. Steps blocked by paclobutrazol indicated with Geranyl diphosphate synthase (GPS), Farnesyl diphosphate synthase (FPS), Geranyl geranyl diphosphate synthase (GGPS), ent-copalyl-diphosphate synthase (CPS), ent-kaurene synthase (KS), ent-kaurene oxidase (KO), ent-kaurenoic acid oxidase (KAO), Geranyl geranyl reductase (GGRS), Chlorophyll synthase (CHL) and Phytoene synthase (PSY) are the enzymes involved in the terpenoid pathway. ABA 8′-hydroxylase (ABA 8′OH) involved in the enzymatic degradation of ABA into Phaseic acid. KO, KAO and ABA 8′OH are the enzymes inhibited upon PBZ application