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

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.

Putative WRKYs associated with regulation of fruit ripening revealed by detailed expression analysis of the WRKY gene family in pepper

“…Although a comprehensive study of CaWRKYs in pepper was recently performed35, little focus was placed on comprehensive expression profiles of the entire WRKY gene family in tissues and their response to abiotic stresses. The global analysis of the CaWRKY gene expression pattern will facilitate the functional studies of pepper CaWRKY s. We identified 61 CaWRKY s and analyzed the expression profiles of all the members in various tissues using RNA-seq and quantitative real-time PCR (qPCR), with emphasis on fruit maturation.…”

Genome-wide analysis of WRKY gene family in the sesame genome and identification of the WRKY genes involved in responses to abiotic stresses

“…This variant of the WRKY domain has also been found in pepper [9], tea [36], and apple proteins [13]. Waterlogging induced the expression of SiWRKY59 and SiWRKY60 (Fig.…”

“…Several families of genes are particularly associated with significant improvements in abiotic stress tolerance, including the WRKY, NAC, and ERF gene families [4][5][6]. Numerous studies have demonstrated that WRKY genes are expressed strongly and rapidly in response to particular abiotic stresses, including wounding, waterlogging, drought, and salt stress [7][8][9]. In Arabidopsis, AtWRKY30 is induced by methyl viologen, hydrogen peroxide, arsenic, drought, sodium chloride, and mannitol [10].…”

Genome-wide identification of the potato WRKY transcription factor family

“…Previous studies identified at least 72 WRKY family genes in Arabidopsis thaliana [8], about 100 in Populus [11], 59 in Vitis vinifera [12], 81 in Solanum lycopersicum [13] and 71 in Capsicum annuum [14]. Previous studies of WRKY family evolution showed that Group I was an ancestral group.…”