Identification and Characterization of the CCoAOMT Gene Family in Apple, Chinese White Pear, and Peach

Lignin is one of the main components of plant cell walls, which provides mechanical support for plants and also contributes to resisting against plant pathogenic fungi. In the fruit industry, the lignin content can affect the quality of fruit. The biosynthesis of lignin involves a variety of enzymes, of which caffeoyl-CoA 3-O-methyltransferase (CCoAOMT) is a class of methyltransferases that plays an essential role in lignin biosynthesis. Studies have been conducted on the CCoAOMT gene family in several species, including arabidopsis (Arabidopsis thaliana), black poplar (Populus nigra), and cotton (Gossypium hirsutum). Still, there is relatively little research on this gene family in the Rosaceae. In this study, we used bioinformatics to identify and characterize the CCoAOMT gene family in apple (Malus domestica), chinese white pear (Pyrus bretschneideri), and peach (Prunus persica). In total, 35 CCoAOMT genes were identified in the three Rosaceae species: 8 from chinese white pear, 12 from apple, and 15 from peach. By using structure analysis and collinearity analysis, we found 12 conserved motifs and 12 pairs of CCoAOMT genes with collinearity. In the phylogenetic tree, the gene family was mainly divided into two groups. The genes had different expression patterns during the growth and development stage of fruit, a finding that is consistent with the pattern of lignin accumulation. This study will be beneficial for further study of CCoAOMT genes.