Identification of DREB gene family in foxtail millet (Setaria italica) and analysis of its expression pattern in response to abiotic stress

Dehydration response element binding proteins (DREBs) play a vital role in transcriptional regulators in enhancing plant tolerance to abiotic stress. To investigate the biological functions of the DREB gene family ( SiDREBs ) in foxtail millet ( Setaria italica ), this study performed bioinformatics and gene expression analysis on SiDREBs under abiotic stress. A total of 166 family members of SiDREBs were identified, which were classified into six subfamilies. SiDREBs were unevenly distributed on nine chromosomes, and were designated as SiDREB1 – 166 based on their chromosomal positions. Covariance analysis revealed that SiDREBs were much more closely related to monocotyledonous plants sorghum, maize, and rice than to dicotyledonous plants Arabidopsis thaliana , tomato, and soybean. Promoter cis -acting element analysis showed that SiDREBs contained stress-related cis- acting elements. Under saline-alkali stress, SiDREB153 exhibited significantly different expression levels between the resistant and susceptible materials, indicating that it plays a positive regulatory role in the response of foxtail millet to saline-alkali stress. Among different abiotic stresses, the expression of SiDREB80 increased under drought, saline-alkali, and shade stress, that of SiDREB4/129/131 rose under saline-alkali and high temperature stress, and that of SiDREB159 increased under herbicide and saline-alkali stress. These genes play an important role in the response of foxtail millet to stress. These findings provide a theoretical basis for further studies on the function of SiDREBs in response to abiotic stress.