Identification of R2R3-MYB Gene Family and Functional Analysis of Responses of S22 Subfamily to Abiotic Stresses in Dandelion (Taraxacum mongolicum Hand.-Mazz.)

Dandelions possess a wide range of medicinal properties and demonstrate remarkable adaptability and tolerance to salinity and alkalinity. <i>MYB</i> genes in plants are implicated in growth, differentiation, metabolism, and responses to both biotic and abiotic stresses. The function of MYB genes in dandelions, particularly the R2R3-MYB gene family, requires further investigation. In this study, we identified a total of 130 members of the dandelion R2R3-MYB gene family at the genome-wide level, all of which were mapped to eight dandelion chromosomes. MEME analysis revealed that TmR2R3-MYB proteins contain three conserved motifs. Phylogenetic analysis categorized all TmR2R3-MYBs into 29 subfamilies. Transcriptomic studies in different tissues indicated that TmR2R3-MYBs exhibit distinct expression patterns in different tissues, indicating their diverse functions in dandelions. Notably, <i>TmMYB44</i> from the S22 subfamily displayed the highest expression level in roots. Additionally, six representative TmR2R3-MYBs were selected from the S22 subfamily for expression profiling under salinity and alkalinity treatments. The results demonstrated that the TmR2R3-MYBs from the S22 subfamily are involved in the response to salinity and alkalinity stress. These findings provide a basis for further exploration of the functions of TmR2R3-MYBs in abiotic stress tolerance.