Genome-Wide Identification, Structural, and Gene Expression Analysis of BRI1-EMS-Suppressor 1 Transcription Factor Family inCucumis sativus

BRASSINOSTEROID INSENSITIVE1-EMS-suppressor 1 (BES1) is an essential regulator downstream of brassinosteroid signaling and plays important roles in plant stress response, growth, and development. To date, the regulation mechanisms of BES1 transcription factors have been identified and elucidated in model plants Arabidopsis and rice. However, little information is available regarding the BES1 family inCucumis sativus. Therefore, this study conducted a genome-wide analysis of BES1 genes in cucumber. In cucumber, a total of six CsBES1 genes were identified, and their phylogenetic relationships, gene structures, andcis-elements in promoters were studied.CsBES1genes were distributed on four of seven chromosomes. Gene structure analysis showed that the intron-exon model ofCsBES1genes was conserved and the CsBES1 protein contained a DUF822-conserved motif. Promotercis-element prediction showed that plenty of developmental and stress- and hormone-related elements have been found in promoter regions ofCsBES1genes. Meanwhile, BES1 was divided into three groups (I, II, and III) on the basis of phylogenetic relationship analysis in six plant species. In addition,CsBES1gene expression patterns were confirmed by transcription database and qRT-PCR analysis; the results showed that the expression ofCsBES1genes had not only tissue-specific expression but also different types ofCsBES1isoform which might respond to specific plant stresses. In summary, genome-wide identification, phylogeny, gene structure, and expression profile analysis ofCsBES1genes in cucumber provided a referable theoretical information for further functional study ofCsBES1genes and further facilitated the molecular breeding of cucumber.