Genome-Wide Identification and Transcriptomic Analysis of MYB Transcription Factors in Seashore Paspalum Under Salt...

The MYB transcription factor family plays crucial roles in plant growth, development, and responses to biotic and abiotic stresses. Seashore paspalum (Paspalum vaginatum) is a halophytic grass species with remarkable salt tolerance, yet its MYB gene family has not been systematically characterized. In this study, we conducted a genome-wide identification of MYB genes in seashore paspalum using a Hidden Markov Model (HMM)-based approach, resulting in the identification of 157 PvMYB genes. Phylogenetic and conserved motif analyses revealed distinct subfamily groupings and evolutionary relationships within the PvMYB family. Promoter analysis indicated that PvMYB genes contain multiple cis-acting elements responsive to light, hormones, and abiotic stresses, suggesting their potential regulatory roles under salt stress. Collinearity and duplication analyses demonstrated that gene duplication events contributed to the expansion of the PvMYB family. Moreover, protein interaction network prediction suggested that PvMYB73 may interact with key regulatory proteins such as BZIP8 and DREB1F involved in salt stress signaling. Transcriptome and reverse transcription quantitative PCR (RT-qPCR) analyses showed that PvMYB90, PvMYB123, and PvMYB150 were upregulated in leaves and roots under salinity stress, while PvMYB85 and PvMYB90 were experimentally validated to localize in the nucleus and function in salt tolerance regulation. Collectively, this study provides the first comprehensive characterization of the MYB gene family in seashore paspalum and offers valuable insights into the molecular mechanisms underlying salt tolerance in halophytic grasses.