Schematic presentation of the gene constructs used. The constructs used to generate the transgenic plants used for Figures 4, 5 and 6 incorporated either the p35S or the Arabidopsis pIRX5 promoter. The UGE2 and GalS1 proteins were expressed with tags as indicated in the two upper constructs. The pIRX5:NST1-UGE2 construct had the two open reading frames separated by a 2A sequence. For additional details see Methods and Table 2.