“…The main anthocyanins in sweet potato were mono- and diacylated derivatives of cyanidins and peonidins (Montilla et al, 2010 ) that were synthesized via the flavonoid pathway, which has been widely studied in a variety of plants like Arabidopsis (Lepiniec et al, 2006 ), strawberry (Aharoni et al, 2001 ), Passiflora edulis Sims (Qiu et al, 2020 ), and purple wheat (Wang et al, 2021 ). In sweet potato, the key structural genes related to the flavonoid biosynthetic pathway, such as phenylalanine ammonia lyase ( IbPAL ) (Yu et al, 2021 ), chalcone isomerase ( IbCHI ) (Guo et al, 2015 ), dihydrokaempferol reductase ( IbDHKR ) (Liu et al, 2017 ), dihydroflavonol 4 reductase ( IbDFR ) (Wang et al, 2013 ), anthocyanidin synthase ( IbANS ) (Zhou et al, 2009 ), flavonoid 3′-hydroxylase ( IbF3'H ) (Zhou et al, 2012 ), anthocyanidin 3-O-glucoside-2″-O-glucosyltransferase ( Ib3GGT ) (Wang et al, 2018b ), and UDP-glucose: flavonoid 3-O-glucosyltransferase ( IbUF3GT ) (Hu et al, 2016 ), have been isolated and verified with gene function illustration. In addition to structural genes, many transcription factors (TFs) have also been reported to regulating the expression of flavonoid biosynthetic genes.…”