Genome-Wide Identification, Evolution, and Expression Characterization of the Pepper ( spp.) Gene Family.

MADS domain transcription factors play roles throughout the whole lifecycle of plants from seeding to flowering and fruit-bearing. However, systematic research into - genes of the economically important vegetable crop pepper ( spp.) is still lacking. We identified 174, 207, and 72 - genes from the genomes of . , . , and . , respectively. These 453 - genes were divided into type I (Mα, Mβ, Mγ) and type II (MIKC* and MIKC) based on their phylogenetic relationships. Collinearity analysis identified 144 paralogous genes and 195 orthologous genes in the three Capsicum species, and 70, 114, and 10 - genes specific to . , . , and . , respectively. Comparative genomic analysis highlighted functional differentiation among homologous - genes during pepper evolution. Tissue expression analysis revealed three main expression patterns: highly expressed in roots, stems, leaves, and flowers (//); only expressed in roots; and specifically expressed in flowers (//). Protein interaction network analysis showed that type II CaMADS mainly interacted with proteins related to flowering pathway and flower organ development. This study provides the basis for an in-depth study of the evolutionary features and biological functions of pepper - genes.