Gene Encodes SG7 R2R3-MYB Transcription Factor from Tartary Buckwheat ( Gaertn.) to Promote Flavonol Accumulation in Transgenic .

Tartary buckwheat ( Gaertn.) is a coarse grain crop rich in flavonoids that are beneficial to human health because they function as anti-inflammatories and provide protection against cardiovascular disease and diabetes. Flavonoid biosynthesis is a complex process, and relatively little is known about the regulatory pathways involved in Tartary buckwheat. Here, we cloned and characterized the gene from Tartary buckwheat, which encodes a member of the R2R3-MYB transcription factor family. Amino acid sequence and phylogenetic analysis indicate that FtMYB163 is a member of subgroup 7 (SG7) and closely related to FeMYBF1, which regulates flavonol synthesis in common buckwheat (). We demonstrated that FtMYB163 localizes to the nucleus and has transcriptional activity. Expression levels of in the roots, stems, leaves, flowers, and seeds of were positively correlated with the total flavonoid contents of these tissues. Overexpression of in transgenic enhanced the expression of several genes involved in early flavonoid biosynthesis (, , , and ) and significantly increased the accumulation of several flavonoids, including naringenin chalcone, naringenin-7-O-glucoside, eriodictyol, and eight flavonol compounds. Our findings demonstrate that FtMYB163 positively regulates flavonol biosynthesis by changing the expression of several key genes in flavonoid biosynthetic pathways.