Systematic Analysis of Differentially Expressed Maize ZmbZIP Genes between Drought and Rewatering Transcriptome Reveals bZIP Family Members Involved in Abiotic Stress Responses.

Liru Cao,Tongchao Wang,Pengyu Zhang,Xiaomin Lu,Guorui Wang,Li Wei

doi:10.3390/ijms20174103

Abstract

The basic leucine zipper (bZIP) family of transcription factors (TFs) regulate diverse phenomena during plant growth and development and are involved in stress responses and hormone signaling. However, only a few bZIPs have been functionally characterized. In this paper, 54 maize bZIP genes were screened from previously published drought and rewatering transcriptomes. These genes were divided into nine groups in a phylogenetic analysis, supported by motif and intron/exon analyses. The 54 genes were unevenly distributed on 10 chromosomes and contained 18 segmental duplications, suggesting that segmental duplication events have contributed to the expansion of the maize bZIP family. Spatio-temporal expression analyses showed that bZIP genes are widely expressed during maize development. We identified 10 core ZmbZIPs involved in protein transport, transcriptional regulation, and cellular metabolism by principal component analysis, gene co-expression network analysis, and Gene Ontology enrichment analysis. In addition, 15 potential stress-responsive ZmbZIPs were identified by expression analyses. Localization analyses showed that ZmbZIP17, -33, -42, and -45 are nuclear proteins. These results provide the basis for future functional genomic studies on bZIP TFs in maize and identify candidate genes with potential applications in breeding/genetic engineering for increased stress resistance. These data represent a high-quality molecular resource for selecting resistant breeding materials.

Highlights

Transcription factors (TFs) function in highly conserved network hubs and directly regulate the expression of genes to maintain a suitable living environment inside and outside the plant and control plant growth and development [1]
Principal component, gene co-expression network, Gene Ontology enrichment, and spatio-temporal expression analyses. These analyses identified 15 maize Basic leucine zipper (bZIP) TFs that may be involved in responses to various abiotic stresses
The results indicated that the conservation of the bZIP gene family during evolution has been accompanied by differentiation to some extent

Summary

Introduction

Transcription factors (TFs) function in highly conserved network hubs and directly regulate the expression of genes to maintain a suitable living environment inside and outside the plant and control plant growth and development [1]. When plants are subjected to low temperature, drought, salt stress, or exogenous hormones, TFs are induced to bind to corresponding cis-elements through a series of signal transduction steps to activate or inhibit the generation of the RNA polymerase transcription complex. In this way, TFs regulate the expression of stress-responsive genes to mediate stress responses and improve the stress resistance of plants [3]. Members of the bZIP TF family are classified into subgroups according to sequence similarity, conserved motifs, and DNA binding sites. The Fragaria vesca bZIP TFs have been classified into subgroups: A–I, S, and U [9]

Results

Discussion

Conclusion