Genome-wide identification of WRKY gene family and expression analysis of key WRKY genes in response to Fusarium solani infection in Lycium barbarum

Wolfberry (<i>Lycium barbarum</i>), a member of the Solanaceae family, is recognized as a pioneering tree species for afforestation in saline-alkali soils and holds significant economic value as a forest species. Its fruit is abundant in bioactive compounds that contribute in both ecological health and human well-being. The WRKY gene family has been extensively studied across various species, with its members' functions increasingly elucidated. However, limited research has focused on the role of the <i>WRKY</i> genes of <i>L. barbarum</i>, particularly in resistance to root rot. This study identified the bioinformatics of 104 <i>WRKY</i> genes in wolfberry, encompassing phylogenetics, conserved motifs, gene structures, synteny, and collinearity. Based on structural and phylogenetic, the 104 <i>LbWRKYs</i> are divided into three main groups, Group I, II and III, with 26, 62 and 15 members, respectively. Synteny analysis revealed high homology between LbWRKY and tomato SlWRKY, with a total of 117 pairs of homologous genes identified. Cis-acting elements analysis demonstrated that subgroup II <i>LbWRKY</i> genes contained a higher number of plant hormone-related regulatory elements. Furthermore, 28 <i>LbWRKY</i> genes were found to respond to the infection of <i>Fusarium solani</i>. Protein-protein interaction prediction and correlation analyses revealed that associations between <i>LbWRKY</i> genes and flavonoid and phenylpropanoid synthesis-related genes, and the results showed that <i>LbWRKY8/100/63/84/102/42/45</i> was involved in the mechanism of root rot resistance. Expression analysis following <i>Fusarium solani</i> inoculation confirmed that these genes participate in root rot resistance in <i>L. barbarum</i>. This study provides valuable insights into the functional roles of <i>LbWRKY</i> genes, and establishing a foundation for future research on their involvement in secondary metabolite synthesis and their role in enhancing the disease resistance of <i>L. barbarum</i>.