ULP and DeSI genes are SUMO proteases that function to either mature or deSUMOylate SUMOylated proteins; however, only ULP proteases play a role in maturation [2]. E1 and E2 genes are essential in the SUMO cycle as they encode for proteins that are essential to catalyzing the activation of matured SUMO proteins and facilitating their transfer onto a lysine residue in the target protein through a process called SUMO conjugation [29–32]. Although this process can occur directly through E2, E3 ligase genes are also essential as they encode for proteins that further aid in the transfer of the SUMO protein on the target lysine residue—making the process of SUMO conjugation more efficient [25]. Proteins encoded by E4 genes provide a further step in the SUMO cycle that promotes the formation of SUMO chains [33,35]. All data displayed in this figure were gathered from Ghimire et al. [12] and Li et al. [42]. The colors used in this figure each correlate to a separate plant species and display the number of each of the SUMO machinery components that have been found in the specific species so far. NA is used where currently no data is available for this component in the relevant species.