Genome-Wide Identification of the WRKY Gene Family and Functional Characterization of CpWRKY5 in Cucurbita pepo

The gene family is crucial for regulating plant growth and development. However, the gene is rarely studied in naked kernel formation in hull-less L. (HLCP), a natural mutant that lacks the seed coat. In this research, 76 genes were identified through bioinformatics-based methods in , and their phylogenetics, conserved motifs, synteny, collinearity, and temporal expression during seed coat development were analyzed. The results showed that 76 were identified and categorized into three main groups (I-III), with Group II further divided into five subgroups (IIa-IIe). Moreover, 31 segmental duplication events were identified in 49 genes. A synteny analysis revealed that shared more collinear regions with cucumber than with melon. Furthermore, quantitative RT-PCR (qRT-PCR) results indicated the differential expression of across different varieties, with notable variations in seed coat development between HLCP and CP being attributed to differences in expression. To investigate this further, -overexpression tobacco plants were generated, resulting in increased lignin content and an upregulation of related genes, as confirmed by qRT-PCR. This study offers valuable insights for future functional investigations of genes and presents novel information for understanding the regulation mechanism of lignin synthesis.