Genome-Wide Identification and Expression Analysis of the Class III Peroxidase Gene Family in Potato (Solanum tuberosum L.)

Abstract

Class III peroxidases (PRXs) are plant-specific enzymes and play important roles in plant growth, development and stress response. In this study, a total of 102 non-redundant <i>PRX</i> gene members (<i>StPRXs</i>) were identified in potato (<i>Solanum tuberosum</i> L.). They were divided into 9 subfamilies based on phylogenetic analysis. The members of each subfamily were found to contain similar organizations of the exon/intron structures and protein motifs. The <i>StPRX</i> genes were not equally distributed among chromosomes. There were 57 gene pairs of segmental duplication and 26 gene pairs of tandem duplication. Expression pattern analysis based on the RNA-seq data of potato from public databases indicated that <i>StPRX</i> genes were expressed differently in various tissues and responded specifically to heat, salt and drought stresses. Most of the <i>StPRX</i> genes were expressed at significantly higher levels in root than in other tissues. In addition, real-time quantitative PCR (qRT-PCR) analysis for 7 selected <i>StPRX</i> genes indicated that these genes displayed various expression levels under abiotic stresses. Our results provide valuable information for better understanding the evolution of <i>StPRX</i> gene family in potato and lay the vital foundation for further exploration of <i>PRX</i> gene function in plants.