Genome identification of the DREB gene family in Lycium barbarum and expression analysis in response to leaf blight infection

Background To analyze the characteristics of members of the dehydration responsive element binding protein (DREB) transcription factor family in Lycium barbarum and their response patterns during L. barbarum leaf blight stress, bioinformatics methods were used to conduct a genome-wide identification of the DREB family members in the L. barbarum genome, and systematically analyze the physical and chemical characteristics of proteins, gene structures, phylogenetic evolution, collinearity, and expression patterns of family members under Alternaria tenuis Nees infection. Results A total of 16 non-redundant LbDREB members were identified in the whole genome of L. barbarum , all of which were hydrophilic proteins. They were unevenly distributed on 10 chromosomes of L. barbarum , encoding 174‒503 amino acids, with a relative molecular mass from 19.29‒57.93 kDa and a theoretical isoelectric point from 4.61‒9.66. Phylogenetic analysis showed that the 16 genes could be divided into 6 subgroups (A1‒A6), all of which contained one AP2 conserved domain. Subcellular prediction showed that the vast majority of LbDREB members were located in the nucleus and cytoplasm, and a small number were located in the mitochondria. Sequence lengths of LbDREB members varied greatly, ranging from 348‒3530 bp, and seven pairs of collinear genes were detected. The ratios of non-synonymous mutations (Ka) to synonymous mutations (Ks) (Ka/Ks ratios) were all < 1, indicating that the LbDREB family tended to purify selection during evolution. The 16 LbDREB members showed significantly different expression characteristics at 0, 24, 48, 72, and 120 h after L. barbarum leaf blight pathogen infection. The overall expression level was highest at 120 h of the infection period, and all 16 members are upregulated in expression. Conclusion The results indicated that the LbDREB gene may play an important role in the response of L. barbarum to leaf blight, and provide a reference for further clarification of the functional mechanism of the DREB transcription factor members in L. barbarum .