Genome-wide analysis of the AP2/ERF gene family in maize waterlogging stress response

Members of the APETALA2/ethylene response factor (AP2/ERF) transcription factor superfamily are widely present in plants and play important roles in the plant cell cycle, growth and development, as well as the response to biotic and abiotic stresses. The maize genome project has been completed; therefore, it is possible to identify all of the AP2/ERF genes in the maize genome. In this study, 184 AP2/ERF genes were identified by an in silico cloning method, and were compared with AP2/ERF genes from Arabidopsis, rice, grape and poplar. The 184 AP2/ERF maize genes were classified into four subfamilies: DREB (51), ERF (107), AP2 (22) and RAV (3), as well as one soloist. The amino acid sequence composition, physical and chemical characteristics, phylogenetic trees, conserved domain sequences, functional domains, and chromosomal location of the genes were predicted and analyzed. The 184 AP2/ERF genes are distributed on maize chromosomes 1-10 (31, 21, 13, 19, 22, 18, 21, 16, 11 and 12 genes, respectively). Under 0, 1, 2, 4 h waterlogging stress, the expression of 184 AP2/ERF genes in root of Hz32 inbred line (tolerance to waterlogging) were performed using RNA-sequence, and the result showed that 38 genes were responsive to waterlogging stress. This study lays the foundation for subsequent cloning and investigation of the function of the AP2/ERF genes responding to waterlogging stress in maize.