Supplementary Figure 1: Transgenic plants overexpressing IRT1 + FER1.

(a) Schematic representation of the IRT1 + FER1 T-DNA construct for genetic transformation in cassava. RB and LB symbolizes the right and left borders of the T-DNA respectively, A14: epidermal promoter from Arabidopsis, AtIRT1: iron regulated transporter from Arabidopsis, 3’ A14: 3’UTR from A14, 35 s polyA: 3’ UTR from Cauliflower mosaic virus, patatin: promoter from potato, AtFER1: ferritin storage protein from Arabidopsis, 3’ pat: 3’ UTR from patatin, 3’Nos: 3’ UTR from Agrobacterium. (b-d) Phenotype (e-g) storage roots of 16-week old wildtype TME 204 and IRT1 + FER1 transgenic plants grown under greenhouse conditions. Scale bars at the lower left correspond to 1 cm. (h) Leaf iron (i) leaf zinc (j) storage root iron and (k) storage root zinc concentrations of IRT1 + FER1 transgenic plants. For IRT1 + FER1, n = 4 biologically independent plants. Box and whisker plots were constructed using the R software package The upper whisker extends from the hinge to the largest value no further than 1.5* IQR from the hinge (where IQR is the inter-quartile range, or distance between the first and third quartiles). The lower whisker extends from the hinge to the smallest value at most 1.5* IQR of the hinge. Data beyond the end of the whiskers are called “outlying” points and are plotted individually. Statistical tests were two-sided using Student’s t-test compared to non-transgenic control. *, ** and *** represent significance levels at p ≤ 0.05, p ≤ 0.01 and p ≤ 0.001 respectively.