Phylogenetic Trends of Plant Glutathione peroxidases Revealed by Kohonen Maps (SOM’s)

Abstract

Aims: Glutathione peroxidases in plants have diverse roles in the maintenance of redox homeostasis in conditions of stress. The studies involving this group of enzymes have clearly demonstrated that they are near homologues to animal phospholipid hydroperoxide glutathione peroxidases with cysteine replacing selenocysteine at the sites of interaction for ligands. Phylogenetic insights of the group should provide us with indications regarding the transition of the residues needed for interactions throughout the lineage of plants for this enzyme right from the aquatic members through land plants and to the highest evolved plant groups. Study Design: Glutathione peroxidase gene sets along with other peroxidase gene sets were retrieved from the existing databases and self organizing maps were generated. Place and Duration of the Study: The entire study was performed at the DBT Centre for Bioinformatics, Presidency University, Kolkata for a period of June 2013 to January 2014. Methodology: A comparative clustering was performed using self organizing maps – A technique for comparative unsupervised learning and standard neighbor joining and UPGMA methods of tree generation to identify and delineate clusters of glutathione peroxidase genes. Results: Homology in clustering was observed when the phylogentic tree and the self organizing maps were compared. Specific sister groups were found to occupy unique areas as part of the self organizing map. Conclusion: Observation and results indicate that GPX evolution follows the trend of plant transitory evolution.