Genome-Wide In Silico Analysis and Expression Profiling of Phosphoenolpyruvate Carboxylase Genes in Loquat, Apple, Peach, Strawberry and Pear

Phosphoenolpyruvate carboxylase (PEPC) genes have multiple potential roles in plant metabolism such as regulation and accumulation of organic acids in fruits, movement of guard cells and stress tolerance, etc. However, the systematic identification and characterization of PEPC genes in Rosaceae species i.e., loquat, apple, peach, strawberry, and pear are yet to be performed. In present study, 27 putative PEPC genes (loquat 4, apple 6, peach 3, strawberry 9, and pear 5) were identified. To further investigate the role of those PEPC genes, comprehensive bioinformatics and expression analysis were performed. In bioinformatic analysis, the physiochemical properties, conserved domains, gene structure, conserved motif, phylogenetic and syntenic analysis of PEPC genes were performed. The result revealed that the PEPcase superfamily domain was conserved in all examined PEPC proteins. Most of the PEPC proteins were predicted to be localized in cytonuclear. Genomic structural and motif analysis showed that the exon and motif number of each PEPC gene ranged dramatically, from 8 to 20, and 7 to 10, respectively. Syntenic analysis indicated that the segmental or whole-genome duplication played a vital role in extension of PEPC gene family in Rosacea species. The K-a and K-s values of duplicated genes depicted that PEPC genes have undergone a strong purifying selection. Furthermore, the expression analysis of PEPC genes in root, mature leaf, stem, full-bloom flower, and ripened fruit of loquat, apple, peach, strawberry, and pear was performed. Some genes were differentially expressed in aforementioned plant tissues, signifying their role in plant metabolism. This study provides the first genome-wide identification, characterization, and expression profiling of PEPC gene family in Rosaceae species, and provides the foundation for further functional analysis.