Figure 5

Molecular characterisation of the GRAUX-module. A) GRE, MRE and AuxRE cis-elements within the −300 bp AtGH3.3 promoter region. Framed sequences indicate the positions of the GRE-, MRE- and AuxRE motifs within the AtGH3.3 promoter close to the transcriptional start site (TATA-box is underlined). The present cis-elements are serially numbered. The grey highlighted sequence represents the AtGH3.3 promoter region used as synthetic auxin-responsive GRAUX-module promoter construct. B) Expression profile of the synthetic ProGRAUX: GUS reporter constructs. Number of multimerisations and fold induction values are indicated. C) Auxin inducibility of the ProAtGH3.3 derived GRAUX(4x)-module reporter construct and its mutational derivates. A schematic view of the transfected reporter constructs is given. Mutated cis-elements are indicated by X. White coloured bars represent transfected, mock treated (DMSO) and black coloured bars NAA treated (0.25 μM, 16 h) samples. Presented results were obtained from transient protoplast transfection assays. Given are the mean GUS/NAN values (± SD) from 3 independent experiments. Different letters denote significant differences (p ≤ 0.05; one-way ANOVA followed by Fisher post-hoc test) between the used constructs and treatments. Fold induction values resulting from auxin application are given