Characterization of () gene family and stress induced expression in .

Brassinosteroids (BRs) are a group of plant hormones which play a pivotal role in modulating cell elongation, stress responses, vascular differentiation and senescence. In response to BRs, BRASSINAZOLE-RESISTANT (BZR) transcription factors (TFs) accumulate in the nucleus, where they modulate thousands of target genes and coordinate many biological processes, especially in regulating defense against biotic and abiotic stresses. In this study, 6 BZR TFs of () from a genome-wide survey were characterized by sequence analysis and expression profiling against several abiotic stresses. The results showed that BZR gene family in was slightly smaller compared to and , but all phylogenetic groups were represented. Various systematic in silico analysis of these TFs validated the basic properties of BZRs, whereas comparative studies showed a high degree of similarity with recognized BZRs of other plant species. In the organ-specific expression analyses, 4 were expressed in vascular tissue indicating their possible functions in wood formation. Meanwhile, almost all genes showed differential transcript abundance levels in response to exogenously applied BR, MeJA, and SA, and salt and cold stresses. Besides, protein interaction analysis showed that all genes were associated with BR signaling directly or indirectly. These TFs were proposed as transcriptional activators or repressors of abiotic stress response and growth and development pathways of  by participating in BR signaling processes. These findings would be helpful in resolving the regulatory mechanism of in stress resistance conditions but require further functional study of these potential TFs in .