Genomic survey and gene expression analysis of the MYB-related transcription factor superfamily in potato (Solanum tuberosum L.).

The MYB transcription factors (TFs) comprise a major TF family in the plant kingdom. Studies increasingly show that MYB-related genes drive physiological functions in plants. However, little is known regarding their regulatory networks and downstream pathways in potato. We conducted a genome-wide analysis of MYB TFs and related proteins in potato (Solanum tuberosum, abbreviated as St), and identified 138 StMYB-related TFs that were phylogenetically classified into three distinct subgroups based on highly conserved gene structures, consensus motifs and protein domain architecture. Segmental duplication events were detected in the StMYB-related gene family by collinearity analysis, which likely contributed to the expansion of this family. Synteny analysis indicated that 41 StMYB-related genes were orthologous to Arabidopsis and 24 to wheat. In addition, RNA-seq analysis identified several tissue-specific and abiotic stress-responsive StMYB-related genes. To determine a potential role of these genes in anthocyanin biosynthesis and drought response, we analyzed the transcriptomes of the white, pigmented, drought-sensitive ('Atlantic') and drought-resistant ('Qingshu No.9') tetraploid potato cultivars from three flowering stages: early, peak (full blooms) and late (foliage falling). The interaction networks of StMYB-related proteins that were differentially expressed between pigmented versus white, as well as the drought-tolerant versus sensitive cultivars were also predicted. Our findings lay the foundation for prospective functional studies of potato StMYB-related TFs.