Genome-Wide Identification of bZIP Family Genes Involved in Drought and Heat Stresses in Strawberry (Fragaria vesca).

Xiao-Long Wang,Xinlu Chen,Tian-Bao Yang,Qunkang Cheng,Zong-Ming Cheng

doi:10.1155/2017/3981031

Abstract

Basic leucine zipper (bZIP) genes are known to play a crucial role in response to various processes in plant as well as abiotic or biotic stress challenges. We have performed an identification and characterization of 50 bZIP genes across the woodland strawberry (Fragaria vesca) genome, which were divided into 10 clades according to the phylogenetic relationship of the strawberry bZIP proteins with those in Arabidopsis and rice. Five categories of intron patterns were observed within basic and hinge regions of the bZIP domains. Some additional conserved motifs have been found with the group specificity. Further, we predicted DNA-binding specificity of the basic and hinge regions as well as dimerization properties of leucine zipper regions, which was consistent with our phylogenetic clade and classified into 20 subfamilies. Across the different developmental stages of 15 organs and two types of fruits, the clade A bZIP members showed different tissue-specific expression patterns and the duplicated genes were differentially regulated, indicating a functional diversification coupled with the expansion of this gene family in strawberry. Under normal growth conditions, mrna11837 and mrna30280 of clade A showed very weak expression levels in organs and fruits, respectively; but higher expression was observed with different set of genes following drought and heat treatment, which may be caused by the separate response pathway between drought and heat treatments.

Highlights

The transcription factors containing Basic leucine zipper (bZIP) domain [1, 2] constitute one of the largest gene families in plants
Instability index, isoelectric points, aliphatic index, and grand average of hydropathicity (GRAVY) of candidate FvbZIP proteins were detected in ExPASy ProtParam server
The characteristic parameters of all predicted FvbZIP proteins are listed in Table 1, including chromosome location, protein length, molecular weight, theoretical pI, instability index, aliphatic index, and grand average of hydropathicity (GRAVY)

Summary

Introduction

The transcription factors containing bZIP domain [1, 2] constitute one of the largest gene families in plants. The common feature, bZIP domain with length ranging from 60 to 80 amino acids (aa), includes two unique structures, a highly conserved DNA-binding basic and hinge region and a relatively diversified leucine zipper region [3]. The downstream leucine zipper region is made up of heptad leucine repeats, a repeated pattern of several amino acids, or other hydrophobic amino acids, such as Ile, Phe, and Met [4]. It has been proved that the leucine zipper region is more favorable to constitute an amphipathic-helix with two helical turns within each heptad, because of its special amino acid composition [1, 2]

Methods

Results

Conclusion