Rapid lignification and high lignin accumulation occur in the endocarps of the dove tree (Davidia involucrata) during a short developmental phase. Through transcriptome analysis, we identified a gene named DiCCoAOMT1 that plays a vital role in the rapid lignification process. The expression profile of the DiCCoAOMT1 gene was endocarp-specific, and its encoding product showed strong O-methyltransferase activity in vitro. Here, we overexpressed the DiCCoAOMT1 gene in both Arabidopsis and poplar (Populus tomentosa) to verify its function of lignin...