*2.4. Prediction of the Cis-Regulatory Elements in the Promoter*

To examine the potential cis-elements in the promoters of water lily *SODs*, we obtained the 2 Kb sequence upstream of start codons from each species' genome. Then we used the PlantCARE website (http://bioinformatics.psb.ugent.be/webtools/plantcare/html/ accessed on 6 February 2023) [41], to examine the promoter sequence of each gene, and then we created figure using TBtools (V 1.068).

#### *2.5. Examination of the 3D Structures of Water Lily SOD Proteins*

The comprehension of a protein's functions requires a detailed understanding of its 3D structure. To this end, we analyzed the predicted 3D structures of four water lily species, using the online servers SOPMA and SWISS MODEL, both available through ExPASy at https://www.expasy.org/ accessed on 15 February 2023. Finally, we applied the UCSF Chimera visualization tool to visualize the 3D structures [42].

#### *2.6. Analysis of SOD Gene Structure of Water Lily*

The Gene Structure Display Server (GSDS; http://gsds.cbi.pku.edu.cn/index.php accessed on 19 February 2023) program was used to visualize the organization of exons and introns in the *SOD* genes of water lilies [27].
