Comprehensive Genome-Wide Analysis of the Catalase Enzyme Toolbox in Potato (Solanum tuberosum L.)

Abstract

As antioxidant enzymes, catalase (CAT) defends organisms from oxidative stress caused by excessive production of reactive oxygen species (ROS). These enzymes play important roles in miscellaneous biological processes. However, little is known about the CAT genes in S. tuberosum (StCAT) despite its essential economical rank in the world. So far, abiotic and biotic stresses severely hinder plant growth and development which affects the crop production and quality. To identify the possible roles of CAT genes especially under salt stress, a genome-wide analysis of CAT gene family has been performed in the potato plant. In this study, the StCAT gene’s structure, secondary and 3D protein structure, physicochemical properties, synteny analysis, phylogenetic tree and also expression profiling under various developmental and environmental cues were predicted using bioinformatics tools. The expression analysis by RT-PCR was performed upon a commercial potato cultivar. Three genes encoding StCAT that code for three proteins each of size 492 aa, interrupted by seven introns, have been identified in potatoes. StCAT proteins were found to be localized in the peroxisome which is judged as the main H2O2 cell production site during different processes. Many regulating cis-elements related to stress responses and plant hormones signaling were found in the promoter sequence of each gene. The analysis of motifs and phylogenetic trees showed that StCAT are closer to their homologous in S. lycopersicum and share a 41–95% identity with other plants’ CATs. Expression profiling revealed that StCAT1 is the constitutively expressive member; while StCAT2 and StCAT3 are the stress-responsive members.