Integrated bioinformatics and transcriptomic analysis of sweetpotato MYB genes reveals IbMYB150's role in salt tolerance.

key messageIbMYB genes were systematically identified in sweetpotato, linking their crucial functions in abiotic stress response, with IbMYB150 enhancing salt tolerance in yeast and Arabidopsis. MYB transcription factors play crucial roles in regulating plant responses to various environmental stresses. Sweetpotato is a versatile crop with comprehensive agronomic advantages unmatched by other crops; however, systematic information and functional studies on MYB genes in sweetpotato remain scarce. Herein, employing stringent screening criteria, 339 putative IbMYB genes were identified in sweetpotato genomes, comprising 164 1R-MYB, 166 2R-MYB, 6 3R-MYB, 1 4R-MYB, and 2 5R-MYB. These genes were unevenly distributed across chromosomes, with segment duplications serving as the primary driving force for IbMYB expansion. Conserved motifs and gene structures were characterized within the same subgroups, and synteny detection revealed extensive collinear MYB gene pairs between sweetpotato and other plants, providing insights into IbMYB evolution. Through transcriptome screening and qRT-PCR validation, we identified IbMYB-061/-065/-095/-150/-280L as nuclear-localized transcriptional activators significantly induced by abiotic stress. Heterologous expression in yeast demonstrated that all these selected IbMYBs substantially enhanced salt tolerance. Furthermore, ectopic expression of IbMYB150 in Arabidopsis significantly improved salt tolerance during germination and seedling stages. Collectively, these findings lay the groundwork for elucidating the pivotal roles of IbMYBs in regulating stress tolerance in sweetpotato.