The ankyrin repeat gene family in Capsicum spp: Genome-wide survey, characterization and gene expression profile

Abstract

The ankyrin (ANK) repeat protein family is largely distributed across plants and has been found to participate in multiple processes such as plant growth and development, hormone response, response to biotic and abiotic stresses. It is considered as one of the major markers of capsaicin content in pepper fruits. In this study, we performed a genome-wide identifcation and expression analysis of genes encoding ANK proteins in three Capsicum species: Capsicum baccatum, Capsicum annuum and Capsicum chinense. We identifed a total of 87, 85 and 96 ANK genes in C. baccatum, C. annuum and C. chinense genomes, respectively. Next, we performed a comprehensive bioinformatics analysis of the Capsicum ANK gene family including gene chromosomal localization, Cis-elements, conserved motif identifcation, intron/exon structural patterns and gene ontology classifcation as well as profle expression. Phylogenetic and domain organization analysis grouped the Capsicum ANK gene family into ten subfamilies distributed across all 12 pepper chromosomes at diferent densities. Analysis of the expression of ANK genes in leaf and pepper fruits suggested that the ANKs have specifc expression patterns at various developmental stages in placenta tissue. Our results provide valuable information for further studies of the evolution, classifcation and putative functions of ANK genes in pepper.