Tissue-Specific Expression of StMYB3 Gene Involves Regulating Potato Tuber Skin and Vascular Bundle Anthocyanin Biosynthesis

Anthocyanins not only have a strong antioxidant capacity but also can improve plant resistance to biological and abiotic stresses. Compared with apple, pear and other crops, there are few reports on the regulatory pathways and transcription factors of anthocyanin biosynthesis in potato. In this study, transcriptome analysis was performed on different coloured parts of the same tubers. Differential expression gene analysis showed that the expression of anthocyanin biosynthesis structural genes in red and purple parts of tubers was higher than that in yellow parts. Differential expression transcription factor analysis revealed that a new MYB gene StMYB3 may regulate anthocyanin synthesis in tubers. A transient activation assay showed that StMYB3 could increase the expression level of NtCHS, NtCHI, NtF3H, NtDFR and NtANS in tobacco leaves. Promoter activities of potato structural genes StCHS, StF3'5'H, StDFR and StF3H could be activated by StMYB3 significantly. The promoter sequence of StMYB3 contains auxin-response elements, and GUS staining shows that exogenous auxin can enhance its promoter activity. These provide a theoretical basis for understanding the regulation theory of anthocyanin synthesis and provide a new gene resource for potato molecular breeding with high anthocyanin content.

Automated summary

Anthocyanins not only have strong antioxidant capacity, but also enhance plant resistance to biological and abiotic stresses. This study identified a new MYB gene, StMYB3, as a potential regulator of anthocyanin synthesis in potatoes. Additionally, the study found a significant correlation between the promoter activity of certain potato structural genes and the activation of StMYB3. These findings provide a theoretical basis for understanding the regulation theory of anthocyanin synthesis and offer a new gene resource for molecular breeding of potatoes with high anthocyanin content.