Genome-wide identification and expression analysis of the ERF transcription factor family in pineapple ( (L.) Merr.).

Pineapple ( (L.) Merr.) is an important tropical fruit with high economic value. The quality and yield of pineapple will be affected by various environmental conditions. Under adverse conditions, plants can produce a complex reaction mechanism to enhance their resistance. It has been reported that the member of ethylene responsive transcription factors (ERFs) plays a crucial role in plant developmental process and stress response. However, the function of these proteins in pineapple remains limited. In this study, a total of 74 genes ) were identified in pineapple genome, named from to , and divided into 13 groups based on phylogenetic analysis. We also analyzed gene structure, conserved motif and chromosomal location of , and the within the same group possess similar gene structures and motif compositions. Three genes (, and ) were present on unanchored scaffolds, so they could not be conclusively mapped on chromosome. Synteny and -elements analysis of genes provided deep insight into the evolution and function of pineapple genes. Furthermore, we analyzed the expression profiling of in different tissues and developmental stages, and 22 genes were expressed in all examined tissues, in which five genes (, , , , and ) had high expression levels. Additionally, nine genes were selected for functional verification by qRT-PCR. These results provide useful information for further investigating the evolution and functions of ERF family in pineapple.