Genome-wide investigation of the AP2/ERF gene family in  ginger: evolution and expression profiles during rhizome and inflorescence development

Abstract

Background:AP2/ERF transcription factors perform indispensable functions in various biological processes, such as plant growth, development, biotic and abiotic stresses responses. The AP2/ERF transcription factor family has been identified in many plants, and several AP2/ERF transcription factors from Arabidopsis (Arabidopsis thaliana) have been functionally characterized. However, little research has been conducted on the AP2/ERF genes of ginger (Zingiber officinale), which is an important edible and medicinal horticultural plant. The recently published whole genome sequence of ginger allowed us to study the tissue and expression profiles of AP2/ERF genes in ginger on a genome-wide basis.Results:In this study, 163 AP2/ERF genes of ginger (ZoAP2/ERF) were identified and renamed according to the chromosomal distribution of the ZoAP2/ERF genes. According to the number conserved domains and gene structure, the AP2/ERF genes were divided into three subfamilies by phylogenetic analysis, namely, AP2 (35 members), ERF (125 members) and RAV (3 members). A total of 10 motifs were detected in ginger AP2/ERF genes, and some of the unique motifs were found to be important for the function of ZoAP2/ERF genes.Conclusion:A comprehensive analysis of AP2/ERF gene expression patterns in different tissues and rhizome development stages by transcriptom sequence and quantitative real-time PCR (qRT-PCR) showed that they played an important role in the growth and development of ginger, and genes that might regulate rhizome and flower development were preliminarily identified. This systematic analysis establishes a foundation for further studies of the functional characteristics of ZoAP2/ERF genes and improvement of ginger.