Genome-wide identification of wheat (Triticum aestivum L.) expansin genes and functional characterization of TaEXPB1A

•Including 104 wheat expansins, 1858 expansins were identified in 40 plant species, and they were divided into four groups.•Results showed that EXPA genes probably emerged first, and genes in EXPB, EXLA, and EXLB subgroups might be resulted from gene duplication.•Gene duplication, gene loss, and chromosomal rearrangements occurred during the evolution process of wheat expansins.•Results suggested that wheat expansins involve in plant development, and in response to abiotic stresses.•The phenotypes of transgenic Arabidopsis indicated the functions of TaEXPB1A in root and seed development.