Identification and Analysis of the WRKY Transcription Factor Gene Family in Verbena bonariensis

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 seed germination, etc. However, little information is available about WRKY transcription factors in Verbena bonariensis. . In this study, 70 VbWRKY genes were identified fi ed from the whole genome. The phylogenetic analysis of the WRKY gene family in V. bonariensis and Arabidopsis shows that the WRKY genes in V. bonariensis can be divided into three groups: I, II, and III, which contain 13, 47, and 10 members, respectively. Group II can be further divided into fi ve subclasses: IIa (5), IIb (10), IIc (18), IId (6), and IIe (8). Conservative motif analysis showed that 64 proteins encoded by the 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 VbWRKYs, , 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 about low-temperature, and 30 VbWRKY genes contain low-temperature response elements (LTR), and 61 VbWRKY genes contain abscisic acid response elements (ABRE), indicating that VbWRKY plays a crucial role in plant growth and abiotic stress. According to the expression of VbWRKY in the cold stress and different tissues transcriptome, 70 VbWRKY genes played their respective roles in various tissues and stages to regulate plant growth, Also, some of them participated in the process of cold stress tolerance, 52 VbWRKYs showed significant fi cant differences in expression under cold stress, and 37 VbWRKY genes were up-regulated under cold stress. 9 VbWRKY genes were selected for quantitative real-time PCR (qRT-PCR) analysis under low-temperature stress, and the results showed that all 9 genes were upregulated under low-temperature stress. Ultimately, the present study provides a comprehensive analysis of the predicted V. bonariensis WRKY genes family, which provided a theoretical basis for the study of low-temperature resistance and growth and development of V. bonariensis. .