Identification of salt and drought resistance function of maize transcription factor ZmEREB54

AP2/ERF (APETALA2/ethylene-responsive factor) represents one of the largest transcription factor superfamilies in plants, playing crucial roles in regulating plant growth and development as well as responding to abiotic stresses. Investigating the functions of maize ( Zea mays L.) AP2/ERF family genes will provide novel genetic resources for maize genetic improvement. In this study, the AP2/ERF transcription factor superfamily member ZmEREB54 ( GRMZM2G020054 , Gene ID: 100,278,463) was cloned from maize and was systematically analyzed functionally. The full-length CDS of ZmEREB54 gene was 561 bp, encoding 186 amino acids with a typical AP2/ERF conserved domain. Its promoter region contained cis -acting elements associated with responses to various abiotic stresses and hormones. Maize expression pattern analysis revealed that ZmEREB54 was highly expressed in V12 roots, with significant expression changes under osmotic stress, drought, high salinity, and treatments with abscisic acid (ABA) and jasmonic acid (JA). Phenotypic analysis showed that transgenic Arabidopsis thaliana over-expressing ZmEREB54 exhibited significantly longer roots compared to wild-type plants under high salinity, drought, osmotic stress, and hormone treatments (JA, ABA). Stress-responsive marker genes RD29A and RD22 were upregulated in the transgenic A. thaliana lines. The significantly decreased malondialdehyde (MDA) accumulation and markedly increased peroxidase (POD) activity in transgenic A. thaliana further demonstrate the improvement of its stress tolerance. Yeast two-hybrid (Y2H) assays revealed an interaction between ZmEREB54 and ZmMADS24.6, suggesting potential cooperative regulation of ZmEREB54 and ZmMADS24.6 in maize root development and stress responses. This study establishes a solid foundation for further clarifying the biological functions and molecular mechanisms of ZmEREB54 in regulating maize root growth and development, as well as responding to drought and salt stresses.