Comprehensive Analysis of the R2R3-MYB Transcription Factor Gene Family in Salvia miltiorrhiza and the Regulatory Role of SmMYB50 in Salvianolic Acid Metabolism
摘要
(TF) R2R3-MYB transcription factors (TFs) play crucial roles in regulating plant secondary metabolism, which is vital for growth, development, and stress responses. Salvia miltiorrhiza, a medicinal plant, is known for its bioactive compounds such as salvianolic acids. Understanding the R2R3-MYB TF family in S. miltiorrhiza could provide insights into the regulation of secondary metabolism and contribute to quality improvement in this important medicinal plant.
Methods and ResultsWe conducted a comprehensive analysis of the R2R3-MYB TF family in S. miltiorrhiza, identifying 431 MYB-like TFs, including 149 R2R3-MYB TFs. Phylogenetic analysis classified these TFs into 27 distinct groups. Chromosomal localization analysis revealed their widespread distribution across all chromosomes. Structural analysis showed that most R2R3-SmMYB genes contain untranslated regions (UTRs) and conserved motifs, with motif5 potentially playing a key role in differentiation. Interspecific collinearity analysis demonstrated the highest collinearity between S. miltiorrhiza and Salvia baicalensis, with 12 intraspecific collinear genes exhibiting interspecific collinearity with multiple species. Promoter analysis identified abundant light- and hormone-responsive elements, particularly MeJA-responsive elements. Expression profiling highlighted SmMYB50 as highly responsive to MeJA, ABA, and YE induction, promoting salvianolic acid accumulation. Transgenic validation confirmed that SmMYB50 activates key biosynthetic genes such as SmCYP98A14, crucial for SalB synthesis.
ConclusionsOur findings provide valuable insights into the functional roles of R2R3-SmMYB-TFs in regulating secondary metabolism in S. miltiorrhiza. SmMYB50 was identified as a key regulator, offering new directions for future research on metabolic pathways and quality improvement in this important medicinal plant.