Genome-Wide Identification of WRKY Transcription Factor Family and Its Expression Patterns in Dalbergia odorifera T. Chen

Dalbergia odorifera is a valuable material used in the crafting of luxury furniture, and the chemical constituents from heartwood possess significant medicinal value. The WRKY gene family, one of the most extensively studied gene families, plays an important role in plants. However, a comprehensive genome-wide identification of the WRKY gene family in D. odorifera has not been reported yet. In this study, a total of 99 WRKY genes were identified in D. odorifera. The DoWRKY genes were categorized into three primary groups with five subgroups. A collinearity analysis revealed 38 segmental duplications and 3 tandem duplications within the DoWRKY genes, indicating the pivotal role of segmental duplication in gene family expansion. Through the analysis of DoWRKY transcriptomic data across diverse tissues and under wounding stress, we found that only eight genes were universally expressed, while a subset displayed distinct tissue-specific patterns. Notably, DoWRKY41 was exclusively expressed in leaves; DoWRKY04 was solely in roots; and DoWRKY17, DoWRKY28, DoWRKY47, and DoWRKY67 were uniquely in flowers. Furthermore, we identified 24 WRKY proteins that tightly respond to wounding stress (20 upregulated; 4 downregulated). This comprehensive investigation offered valuable insights into the WRKY gene family of D. odorifera, serving as a foundational resource for forthcoming explorations into the functional roles of these genes amid wounding stress.