Genome-Wide Identification and Expression Analysis of WRKY Gene Family in Capsicum annuum L.

Wei-Ping Diao,Ge Wei,Bao-Gui Pan,Guang-Jun Guo,John C Snyder,Shu-Bin Wang,Jin-Bing Liu

doi:10.3389/fpls.2016.00211

Abstract

The WRKY family of transcription factors is one of the most important families of plant transcriptional regulators with members regulating multiple biological processes, especially in regulating defense against biotic and abiotic stresses. However, little information is available about WRKYs in pepper (Capsicum annuum L.). The recent release of completely assembled genome sequences of pepper allowed us to perform a genome-wide investigation for pepper WRKY proteins. In the present study, a total of 71 WRKY genes were identified in the pepper genome. According to structural features of their encoded proteins, the pepper WRKY genes (CaWRKY) were classified into three main groups, with the second group further divided into five subgroups. Genome mapping analysis revealed that CaWRKY were enriched on four chromosomes, especially on chromosome 1, and 15.5% of the family members were tandemly duplicated genes. A phylogenetic tree was constructed depending on WRKY domain' sequences derived from pepper and Arabidopsis. The expression of 21 selected CaWRKY genes in response to seven different biotic and abiotic stresses (salt, heat shock, drought, Phytophtora capsici, SA, MeJA, and ABA) was evaluated by quantitative RT-PCR; Some CaWRKYs were highly expressed and up-regulated by stress treatment. Our results will provide a platform for functional identification and molecular breeding studies of WRKY genes in pepper.

Highlights

Received: 16 October 2015 Accepted: 07 February 2016 Published: 23 February 2016Citation: Diao W-P, Snyder JC, Wang S-B, Liu J-B, Pan B-G, Guo G-J and Wei G (2016) Genome-Wide Identification and Expression Analysis of WRKY Gene Family in Capsicum annuum L.Front
It was observed in our investigation, and 15.5% (11/71) CaWRKY genes were found to evolve from tandem gene duplication (Figure 1)
Tandem gene duplication may have played an important role in WRKY gene family expansion in pepper

Summary

Introduction

Received: 16 October 2015 Accepted: 07 February 2016 Published: 23 February 2016Front. Transcription factors are a class of proteins that regulate gene expression. They are usually composed of at least four discrete domains: a DNA binding site, a transcription activation domain, an oligomerization site and a nuclear localization signal. These domains operate together to regulate many physiological and biochemical processes, and to activate and/or repress transcription in response to endogenous and exogenous stimuli. These transcription factors facilitate the evolution and adaption of more complex developmental systems

Methods

Results

Conclusion