Genome-wide identification of the Medicago sativa L. MYB family and its transcriptional dynamics during pollen development.

BACKGROUND

The myeloblastosis (MYB) gene family plays crucial roles in the development of anthers and the establishment of pollen morphology during plant growth. However, little is known about the role of MYB transcription factors in pollen development in alfalfa (Medicago sativa L.).

RESULTS

In this study, we identified 161 MsMYBs in the alfalfa genome, including 34 1R-MYBs, 123 R2R3-MYBs, 3 3R-MYBs, and 1 4R-MYBs (categorized by the number of repeats). These were classified into six subfamilies based on the phylogenetic analysis, conserved structural domains, and gene structures. All MsMYBs were predicted to be hydrophilic and localized in the cell nucleus. The promoter regions contained three classes of cis-regulatory elements related to pollen development, as well as a variable set of functionally diverse elements, including hormone responsiveness, growth and development, and stress responsiveness elements. A transcriptome and qRT-PCR analysis revealed 12 MsMYBs with anther-specific expression and exhibited distinct expression patterns. Some MsMYBs showed a close phylogenetic relationship with Arabidopsis MYBs related to pollen development, such as MsMYB49 and MsMYB100, were found to be localized in the nucleus upon subcellular localization analysis. This genetic proximity suggests a potential role for these MsMYBs in the developmental processes of pollen.

CONCLUSIONS

This study provides a comprehensive understanding of MsMYBs in alfalfa and elucidates their potential roles and expression patterns in pollen development.