Genome-wide identification reveals that BZR1 family transcription factors involved in hormones and abiotic stresses response of lotus (Nelumbo)

Abstract Background The brassinazole-resistant (BZR) transcription factors (TFs) are key components of BR signaling, which play an important role in regulating plant growth, development and responding to abiotic stress. However, the functional study of BZR transcription factors in lotus has not been reported.Results A total 10 BZR1 genes (4 NnBZR1 and 6 NlBZR1) were identified from the genomes of two lotus species (Nelumbo nucifera and Nelumbo lutea). The construction of phylogenetic tree showed that the 10 BZR1 genes of lotus were divided into 4 groups, the NnBZR1s and NlBZR1s were unevenly distributed on 3 and 4 chromosomes, respectively. Gene structure analysis showed that motif 1 and motif 9 are highly conserved in lotus BZR1 protein, which might be related to the conserved domain BES_N of BZR1. The analysis of promoter cis-acting elements showed that the promoters of most of the BZR1 genes in lotus contained elements related to light-responsive, ABA-responsive and abiotic stress-responsive, indicating that the BZR1 gene of lotus played an important role in its response to abiotic stress. The expression profiles of different tissues indicated that the NnBZR1 genes were mainly expressed in the carpel, apical bud and seed coat, suggesting that the NnBZR1 genes may play an important role in reproduction and dormancy in lotus. The responses of 6 genes NnBZR1s, Nn1g01524.2 and Nn5g29512.5 to BR, ABA and 4 abiotic stresses (Cold, PEG6000, Cd and NaCl) were analyzed by qRT-PCR. The qRT-PCR results were further verified that the lotus BZR1 genes play an important role in responding to gene signals and resisting abiotic stress.Conclusions This study laid the foundation for further research on the function of lotus BZR1 genes, and provided a theoretical basis for future breeding and horticultural applications.