Unraveling the Role of MYB Transcription Factors in Abiotic Stress Responses: An Integrative Approach in Eugenia uniflora L.

MYB transcription factors (TF) play crucial roles in regulating gene expression and orchestrating responses to abiotic and biotic stresses in plants. MYBs were demonstrated to be involved in land plant adaptation. However, little is known about these proteins in native species from heterogeneous environments. Eugenia uniflora (Myrtaceae) is widely distributed in diverse environments within the Atlantic Forest Domain (AFD). In this work, we identified 147 MYB genes in E. uniflora using an integrative approach involving the genome, transcriptome, and phylogenetics analyses. A phylogenetic approach including MYBs from E. uniflora, Eucalyptus grandis, Arabidopsis thaliana, Solanum lycopersicum, Oryza sativa, Vitis vinifera, and Medicago truncatula allowed us to classify the EunMYB in 39 subfamilies already described. The RNA-seq data analysis unveiled the expression patterns of MYB genes under stress conditions in E. uniflora and Eucalyptus grandis. We found 50 EunMYB genes differentially expressed (DE) in E. uniflora under drought stress. In E. grandis, 11 genes were found to be DE under cold and 25 under heat stress. Integrating the expression data, phylogenetic relationships, and the available data from the literature, we highlight the potential MYBs of E. uniflora that may be acting in resistance to abiotic stress, enabling adaptation to diverse environmental conditions.