Fig. 5

Phylogenetic analysis of GA3ox proteins and expression profiling of SmGA3ox genes. a: Phylogentic relationship of GA3ox proteins in Arabidopsis thaliana (At), Cucumis sativus (Cus), Cucurbita maxima (Cum), Gossypium hirsutum (Gh), Malus domestica (Md), Oryza sativa (Os), Physcomitrella patens (Pp), Pisum sativum (Ps), Rorippa aquatica (Ra), Salvia miltiorrhiza (Sm), Spinacia oleracea (So), Theobroma cacao (Thc), and Zea mays (Zm). The unrooted neighbor-joining tree was constructed using the MEGA 6.0 [64]. SmGA3ox1 and SmGA3ox2 from S. miltiorrhiza are in bold. Clades 1–3 indicate the three clades identified. b and c: Fold changes of SmGA3ox1 (b) and SmGA3ox2 (c) in roots (Rt), stems (St), leaves (Le) and flowers (Fl) of S. miltiorrhiza plants. The expression levels were analyzed using the quantitative RT-PCR method. Expression level in leaves was arbitrarily set to 1 and the levels in other tissues were given relative to this. Error bars represent standard deviations of mean value from three biological and four technical replicates. ANOVA (analysis of variance) was calculated using SPSS. P < 0.05 was considered statistically significant. d–i: Responses of SmGA3ox genes to exogenous GA3 treatment. Fold changes of SmGA3ox1 (d–f) and SmGA3ox2 (g–i) transcripts in roots, stems and leaves of S. miltiorrhiza plantlets treated with 100 μM GA3 for 0, 12, 24 and 48 h are shown. The expression levels were analyzed using the quantitative RT-PCR method. Expression level in tissues without treatment (0 h) was arbitrarily set to 1 and the levels in tissues from GA3-treated plantlets were given relative to this. Error bars represent standard deviations of mean value from three biological and four technical replicates. ANOVA (analysis of variance) was calculated using SPSS. P < 0.05 (*) and P < 0.01 (**) was considered statistically significant and extremely significant, respectively