Genome-Wide Identification and Expression Profiling of B3 Transcription Factor Genes in Prunus armeniaca

Abstract

The B3 superfamily, which belongs to the plant-specific transcription factors, is widely involved in multiple biological processes. In apricot (Prunus armeniaca), the classification, structure, and function of the B3 superfamily are not yet clear. In this study, a total of 75 B3 genes were identified from the apricot genome. The apricot B3 superfamily can be divided into five subfamilies, i.e., REM, ARF, ABI3, RAV, and HSI, and genes in the same subfamily have similar structures. The distribution of B3 genes on chromosomes presents a clustering phenomenon. Tandem duplication is the main mode of apricot B3 family expansion, and gene duplication mainly occurs in the REM and ARF subfamilies. Many B3 genes originated from a common ancestor of Arabidopsis and apricot before lineage divergence, and ancestor genes expanded fewer times in apricot than in Arabidopsis. Gene ontology analysis showed that apricot B3 genes were closely related to vernalization, flower development, and shoot system development. PaABI3-1 and PaABI3-2 might play a positive regulation role in the transcription of PaOleosin, which encodes a lipid body protein. This study lays a foundation for the further study of the B3 superfamily function in apricot, especially the specific functions of the ABI3 subfamily in apricot kernel oil storage.