The Expression of Is Essential to Maintain the Purple Color of Leaf and Storage Root in Sweet Potato [ (L.) Lam].

was one of the major anthocyanin biosynthesis regulatory genes that has been identified and utilized in purple-fleshed sweet potato breeding. At least three members of this gene, namely, , , and , have been reported. We found that and are not necessary for anthocyanin accumulation in a variety of cultivated species (hexaploid) with purple shoots or purplish rings/spots of flesh. Transcriptomic and quantitative reverse transcription PCR (RT-qPCR) analyses revealed that persistent and vigorous expression of is essential to maintain the purple color of leaves and storage roots in this type of cultivated species, which did not contain gene members. Compared with , is an early response gene of anthocyanin biosynthesis in sweet potato. It cannot exclude the possibility that other participate in this gene regulation networks. Twenty-two genes were identified from 156 to be highly positively or negatively correlated with the anthocyanin content in leaves or flesh. Even so, the was most coordinately expressed with anthocyanin biosynthesis genes. Differences in flanking and coding sequences confirm that , the highest similarity genes of , are not the members of . This phenomenon indicates that there may be more members of in sweet potato, and the genetic complementation of these members is involved in the regulation of anthocyanin biosynthesis. The 3' flanking sequence of is homologous to the retrotransposon sequence of . Transposon movement is involved in the formation of multiple members of . This study provides critical insights into the expression patterns of , which are involved in the regulation of anthocyanin biosynthesis in the leaf and storage root. Notably, our study also emphasized the presence of a multiple member of for genetic improvement.