Genome-wide characterization of the WRKY transcription factor family in Salvia sclarea reveals candidate regulators of sclareol biosynthesis

As an economically valuable multipurpose plant, Salvia sclarea is prized in the fragrance and pharmaceutical industries for its production of various terpenoids, notably sclareol. WRKY transcription factors regulate plant growth, stress responses, and secondary metabolism, but the WRKY gene family in S. sclarea has not been systematically characterized. Here, we performed a comprehensive identification and evolutionary analysis of 37 WRKYs in S. sclarea . Phylogenetic analysis classified these SsWRKYs into seven groups. They are unevenly distributed across 10 chromosomes and have expanded through dispersed , whole-genome or segmental duplication. Structural analysis showed that 43.24% of SsWRKYs contain two introns, with groups I/IId exhibiting more complex structures, while the conserved WRKY domain remained present in all members. Cis-element predictions suggest that SsWRKYs respond to diverse physical and chemical signals. Tissue-specific expression profiling clustered the SsWRKYs into three distinct groups. Notably, SsWRKY19 showed high expression across all tissues. Co-expression analysis and RT-qPCR validation confirmed that the expression patterns of SsWRKY25, SsWRKY17, SsWRKY21 , and SsWRKY5 were similar to sclareol biosynthetic enzyme genes, with the highest relative expression levels in flower and bract, suggesting their potential regulatory role in sclareol biosynthesis. The predicted protein-protein interaction network indicated that 37 SsWRKY proteins interact with 447 proteins, possibly mediating stress and hormone response networks in S. sclarea . This study provides the first genome-wide systematic analysis of WRKYs in S. sclarea and identifies candidate SsWRKYs involved in regulating sclareol biosynthesis, laying a theoretical foundation for future molecular breeding and elucidation of the sclareol regulatory network in S. sclarea .