Figure 1
Schematic representation of gibberellin biosynthesis pathway and GA2-oxidase gene family in plant. (A) The major GA biosynthesis and metabolic pathway showing intermediate molecules, final products, and responsible enzymes for every step. GGDP, geranylgeranyl diphosphate; CPS, ent-copalyl diphosphate synthase; CDP, ent-copalyl diphosphate; KS, ent-kaurene synthase; KO, ent-kaurene oxidase; KAO, ent-kaurenoic acid oxidase; GA13ox, GA13-oxidase; GA20ox, GA20-oxidase; GA3ox, GA3-oxidase; C20 GA2ox, C20-GA2-oxidase; C19 GA2ox, C19-GA2-oxidase. (B) Phylogenetic relationship of the plant GA2-oxidase gene family. A Maximum-Likelihood tree was constructed using the deduced amino acid sequences of 9 A. thaliana, 16 B. rapa, 33 G. max, 11 L. japonicus, 14 M. truncatula, 11 S. lycopersicon, and 9 V. vinifera putative GA2-oxidase genes. Groups of genes are represented by color arcs. Bootstrap values are indicated on the branches and the branch length reflects the substitution per site. Groups I to III of GA2ox are designated according to the criteria suggested for A. thaliana and S. lycopersicon31. Group IV is comprised of dual specificity GA2-oxidase like (GAOL) genes. Closed symbols denote legume species (G. max, L. japonicus, and M. truncatula) and open symbols denote non-legume species. Genes of M. truncatula are color coded according to their group.
