Cloning and Characterization of the CCoAOMT Gene in Paeonia ostii ‘Fengdan’

(1) Background: the CCoAOMT(caffeoyl CoA O-methyltransferase) gene plays an important role in lignin biosynthesis across plant species, and its function has been characterized in many plant species. (2) Methods: The PoCCoAOMTwas cloned from P. ostii ‘Fengdan’, and its sequence and evolutionary tree were analyzed by bioinformatics methods. Quantitative real-time PCR (qRT-PCR) was used to investigate gene expression across tissues of P. ostii‘Fengdan’, with subsequent measurement of lignin content in different floral organs. (3) Results: the PoCCoAOMT gene contains a 744 bp open reading frame encoding 247 amino acids (molecular weight: 27915.84Da; theoretical isoelectric point : 5.09). Hydrophilicity analysis revealed an average value of -0.292. Phylogenetic analysis indicated that PoCCoAOMT protein shares closest evolutionary affinity with the herbaceous peony (Paeonia lactiflora). qRT-PCR demonstrated highest CCoAOMT expression in pedicels, followed by sepals, receptacle, leaves, and petals. Lignin content variations across tissues correlated with expression patterns. (4) Conclusions: the CCoAOMTgene in P. ostii ‘Fengdan’ is crucial for lignin synthesis.