Genome-Wide Identification, Structural Characterization, and Gene Expression Analysis of BES1 Transcription Factor Family in Tartary Buckwheat (Fagopyrum tataricum)

Abstract

The transcription factor (TFs) BES1, which mediates brassinosteroid (BR) signaling, regulates plant growth and development. However, BES1 genes have not yet been reported in Tartary buckwheat. Here, ten FtBES1 genes were identified in the Tartary buckwheat genome, and they were named FtBES1-1 to FtBES1-10. These genes were divided into four groups according to the classification in Arabidopsis thaliana. Multiple sequence alignment indicated that all BES1 gene members contained the BES1_N structural domain. Phylogenetic relationship FtBES1 genes in the same group had similar gene structures and motifs. An analysis of cis-acting elements demonstrated that the BES1 TFs contains many light-responsive, hormonal, and abiotic stress-responsive elements, etc. The 10 FtBES1 genes were located on four chromosomes of Tartary buckwheat, and gene distribution and synteny analysis revealed that segmental duplications have played important roles in FtBES1 gene family expansion. Tissue specificity revealed that all of the ten FtBES1 members expressed highly in two periods, and relatively high expression levels were observed in mature leaves. Gene expression profiles under different hormone treatments demonstrated that FtBES1 gene family participated in the hormone stress response. This study enriches our knowledge of the Tartary buckwheat BES1 gene family and provides a theoretical basis for analyzing the biological functions and stress tolerance mechanisms of the Tartary buckwheat BES1 transcription factors.