Figure 8.

Pathways of gibberellin synthesis and signaling. (A) Enzymes and intermediate products of the plastidial and cytosolic pathways for isopentenyl pyrophosphate production unify to the plastidal production of ent-kauren as precursor for gibberellin synthesis (GA₁, GA₄, and GA₃) in the cytosol. GA2ox and GAMT mark the biological inactivation of gibberellin. For further details, see text. The arrows are colored according to the species in which the enzymes were found (Fig. 1A). Expression of the identified genes in tomato is shown as explained in Figure 2. (B) The components involved in gibberellin signaling are presented as interaction scheme. Enzyme activities not expressed by any orthologue gene in tomato are indicated in gray.

Abbreviations: Proteins: CLA, cloroplastos alterados; DXR, 1-deoxy-d-xylulose 5-phosphate reductoisomerase; HMGS, hydroxymethylglutaryl-CoA synthase; HMGR, 3-hydroxy-3-methylglutaryl-CoA reductase; IPP, isopentenyl diphosphate isomerase; CPS, ent-copalyl diphosphate synthetase, KS, ent-kaurene synthase; KO, ent-kaurene oxidase; KAO1, ent-kaurenoic acid oxydase; GA20ox, gibberellin 20-oxidase; GA3ox1, gibberellin 3-oxidase; GA2ox, gibberellin 2-oxidase; GAMT, gibberellin methyltransferase; GID, GA insensitive dwarf; GAI, gibberellic acid insensitive; RGA, repressor of GA1–3; RGL, RGA-like; SLY, SLEEPY; PIF, PHY-interacting factor; SPY, SPINDLY; SCL, scarecrow-like.