Identification and analysis of Verbena bonariensis WRKY transcription factor gene family members

Abstract Background: The WRKY transcription factor gene family is one of the unique gene families in plants, it plays an important role in response to abiotic stresses such as cold and drought, hormone signal transduction, regulation of biosynthesis, leaf senescence and seed germination etc. However, little information is available about WRKY transcription factors in Verbena bonariensis. Results: In this study, 70 members of VbWRKY were identified by bioinformatics tool analysis and named VbWRKY1-VbWRKY70. The phylogenetic analysis of the WRKYgene family in Verbena bonariensis and Arabidopsis shows that the WRKY genes in Verbena bonariensis can be divided into three groups: I, II, and III, which contains 13, 47 and 10 members respectivelys. Group II can be further divided into five subclasses: IIa (5), IIb (10), IIc (18), IId (6), and IIe (8). Conservative motif analysis showed that 64 proteins encoded by VbWRKY gene had conserved motifs 1,2 and 3, and the same subclass motif elements were approximately the same. The collinearity analysis showed that there were 44 homologous gene pairs among the VbWRKRs, and these homologous gene pairs may have the same function. Promoter sequence analysis showed that the VbWRKY gene has multiple cis acting elements, including not only cis acting elements related to low temperature and light responses, but also cis acting elements related to hormone regulation, Among them, most VbWRKY genes contain response elements related to low temperature, 30 VbWRKY genes contain low temperature response elements (LTR) , and 61 VbWRKY genes contain abscisic acid response elements (ABRE), indicating that VbWRKYplays a crucial role in plant growth and abiotic stress. According to the expression of VbWRKY in the cold stress transcriptome, 52 VbWRKYsshowed significant differences in expression, and 37 VbWRKY genes were up-regulated under stress Conclusions: Ultimately, the present study provides a comprehensive analysis of predicted Verbena bonariensis WRKY family genes, which provided a theoretical basis for the study of low temperature resistance and growth and development of Verbena bonariensis.