Abstract
Caffeoyl CoA O-methyltransferase (CCoAOMT) is one of the key regulatory enzymes in the lignin biosynthesis pathway. In addition, it participates in the modification of flavonoids, which significantly impacts plant growth, development, and antioxidant capacity, and it plays a crucial role in plant responses to stress and adversity. There is a current research gap in the CCoAOMT gene family of Isatis indigotica, particularly in terms of systematic identification and functional validation. Therefore, this study employed bioinformatics techniques to determine the composition of the CCoAOMT gene family in the Isatis indigotica genome. Eight members of the IiCCoAOMT gene family were identified, and their gene structures and motifs are relatively conserved. These members of the IiCCoAOMT family are located on three different chromosomes (3, 6, and 7) and exhibit significant tandem replication. According to phylogenetic research, IiCCoAOMT is divided into four distinct groups: Ia, Ib, Ic, and II. It is worth noting that the IiCCoAOMT genes in group Ia may be candidate genes involved in flavonoid biosynthesis and indirectly affect the content of flavonoid components., Subsequently, a yeast one-hybrid experiment verified that IiWRKY48 and IiWRKY54 could activate the CCoAOMT gene promoter in Isatis indigotica. These results provide a theoretical basis for understanding the function of CCoAOMT genes.