Fig. 6

Iron-binding ability among representative transgenic plants at the protein extract and tissue levels. a Iron binding assay using crude ste, extract of EV, FerIN, and FerIN/IBPex. Data are presented as the mean (± SE) of three replicates. The percentage values on the top of bars of transgenic lines represent the % increase of iron-binding ability in the transgenic lines compared to the EV control. Different letters are significantly different at p < 0.05 between lines compared by one-way ANOVA with Tukey’s test. b–g Prussian blue staining of the switchgrass stem cross-sections. b EV. c FerIN transgenic lines. d FerIN/IBPes transgenic lines. e to g are higher magnification images of a to c. Scale bars in b–d are 300 µm; scale bars in e–g are 50 µm