Fig. 2

Phylogenetic analysis of KAOs and expression profiling of SmKAO1 and SmKAO2. a: Phylogenetic relationship of KAOs in Aegilops tauschii (Aet), Arabidopsis thaliana (At), Castanea mollissima (Cam), Cucurbita maxima (Cum), Helianthus annuus (Ha), Hordeum vulgare (Hv), Lactuca sativa (Ls), Malus domestica (Md), Oryza sativa (Os), Pisum sativum (Ps), Populus trichocarpa (Pt), Ricinus communis (Rc), S. miltiorrhiza (Sm), Selaginella moellendorffii (Sem), Vitis vinifera(Vv), and Zea mays (Zm). The unrooted neighbor-joining tree was constructed using the MEGA 6.0 [64]. SmKAOs from S. miltiorrhiza are in bold. Clades 1–3 indicate the three clades identified. b and c: Fold changes of SmKAO1 (b) and SmKAO2 (c) genes 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 SmKAOs to exogenous GA3 treatment. Fold changes of SmKAO1 (d–f) and SmKAO2 (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