Fig. 2. Cadmium isotope compositions and concentrations for transgenic yeasts.

Results are shown for yeasts transformed to express either one or two genes from cacao (Tc) or poplar (Pt), which encode expression of metal transporters or sequestering proteins from the NRAMP, HMA and Mt families, in comparison to the control (yeast with the empty vector). Also shown are the data for leaves and roots of 19 cacao clones. The blue bar represents the Cd isotope composition of the CdCl₂ that was added to the yeast culture medium and the hydroponic solution of the cacao plants. Error bars represent the 2s.d. precision of replicate standard measurements that bracketed the sample analyses