Genome-wide analysis of BES1/BZR1 transcription factors and their responses to osmotic stress in Ammopiptanthus nanus

BES1/BZR1s are plant-specific transcription factors and play crucial roles in plant growth, development and response to environmental stress. The Ammopiptanthus nanus (A. nanus) is a relict-xerophyte shrub and tolerates various of abiotic stimuli. However, few genes are identified from A. nanus. To date, the information and function of the AnBES1/BZR1s remains unknown. In the present study, we genome-wide analysed the AnBES1/BZR1s of A. nanus and characterized their properties through sequence analysis and expression profiling against osmotic stress. In total, eight AnBES1/BZR1s were identified from the genome of A. nanus. The most of AnBES1/BZR1s had only one intron. Cis-acting element analysis showed that there were a lot of stress and hormone-responsive elements in the promoter of AnBES1/BZR1s. The phylogenetic tree showed that the AnBES1/BZR1s were clustered into two subfamilies, and shared similar motifs composition and conserved domains in a different subgroup. Two AnBES1/BZR1s (AnBES1/BZR1-1 and -3) were highly expressed in A. nanus. Moreover, the AnBES1/BZR1-3 and -5 were upregulated by PEG and NaCl treatment, respectively. The identification of AnBES1/BZR1s should enable us to further functional study of the AnBES1/BZR1s in A. nanus.

Automated summary

An analysis of AnBES1/BZR1s in Ammopiptanthus nanus showed that most of these transcription factors have only one intron and contain stress and hormone-responsive elements in their promoters. Phylogenetic analysis revealed that AnBES1/BZR1s cluster into two subfamilies, with certain members being significantly upregulated by osmotic stress. This study provides important insights for the further functional study of AnBES1/BZR1s in A. nanus.