Genome-wide evolutionary characterization and expression analyses of WRKY family genes in Brachypodium distachyon.
Bottom Line: Combining the analysis of phylogenetic tree of BdWRKY genes and the result of expression profiling, results showed that most of clustered gene pairs had higher similarities in the WRKY domain, suggesting that they might be functionally redundant.Neighbour-joining analysis of 301 WRKY domains from Oryza sativa, Arabidopsis thaliana, and B. distachyon suggested that BdWRKY domains are evolutionarily more closely related to O. sativa WRKY domains than those of A. thaliana.The results showed that the expression of BdWRKY genes was rapidly regulated by stresses and phytohormones, and there was a strong correlation between promoter cis-elements and the phytohormones-induced BdWRKY gene expression.
Affiliation: Shanghai Chenshan Plant Science Research Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai Chenshan Botanic Garden, 3888 Chenhua Road, Songjiang, Shanghai 201602, China.Show MeSH
Mentions: WRKY domain-containing proteins are extensively found in plants, some fungi, bacteria, and slime moulds. Here, we searched for WRKY genes in six comprehensive datasets, GenBank, UniProt, plantTFDB, GramineaeTFDB, Superfamily, and Phytozome of plant species. In this study, we focused our search and analyses on six major types of model organisms whose genomes have been already sequenced, including red alga, the chlorophytes, the moss, the lycophyte, the eudicots, and the monocots.35,36 The result showed that, as a gene super family that plays important roles in regulation of defence response pathways, WRKY TFs conservatively existed in plant kingdom (Fig. 1). In general, only a few of WRKY homologous genes could be found in algae genome, while plants possess a large number of WRKY genes (Fig. 1). The results indicated that the earliest evolutionary origin of the gene containing the WRKY was from unicellular green algae of chlorophyta, suggesting that WRKY proteins arose before plants transitioned from water to land. With the evolution of species, the land plants have developed a series of highly sophisticated mechanisms that help them to adapt to changing environmental conditions,37 and hence, the number of WRKY TFs increased and they were extensively found in land plants in response to the environmental stimuli and regulation of physiological reactions.Figure 1.
Affiliation: Shanghai Chenshan Plant Science Research Center, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences (CAS), Shanghai Chenshan Botanic Garden, 3888 Chenhua Road, Songjiang, Shanghai 201602, China.