Figure 6.

Evolutionary model of XyG-related genes emergence in Viridiplantae kingdom. The model shows the ancient origins we could trace back of each XyG-related gene families and the major events of XyG evolution in plants. XyG-like (containing only glucose and xylose) emerged in streptophytes algae, XyG (containing glucose, xylose, and galactose) emerged in early embryophytes and the fucosylated XyG emerged in the last common ancestor of spermatophytes. (*) indicates the possible origins of the ancestral genes that gave rise to Spermatophytes α-Fucosyl Transferase (Mur2 orthologs) and α-Fucosylase type I (AtXYL1 orthologs). GH - Glycosyl Hydrolases and GT - Glycosyl Transferases.