*4.1. Plasmid Constructions and Site-Directed Mutagenesis*

To produce recombinant proteins, previously made pET28a-*At*GOX1, pET28a-*At*GOX2 and pET28a-*Zm*GO1 expression plasmids [34] were used as templates to introduce point mutations using specific primers pairs (Table S1) and the QuikChange® II XL site-directed mutagenesis kit (Agilent®, Les Ulis, France), according to the manufacturer's instructions. This strategy generated T4V, T4D, T158V, T158D, S212A, S212D, T265A, T265D (*At*GOX1 and *At*GOX2) and T5V, T5D, T159V, T159D, S213A, S213D, T266A, T266D (*Zm*GO1) mutated proteins. All constructions were subsequently verified by DNA sequencing using T7 and T7-term primers (Table S1).
