Cloning and characterization of a CCoAOMT gene involved in rapid lignification of endocarp in dove tree ( Davidia involucrata Baill.)

摘要

The long period of seed dormancy is one of the most important reasons leading to the low fertility of dove tree ( Davidia involucrata Baill., Davidia hereinafter). During the fruit development process of Davidia , the endocarps will become particularly compact and hard, which was considered as a critical reason for the long seed dormancy of Davidia . However, the biological significance and regulatory mechanism of this process remain unclear. In this study, we identified a CCoAOMT gene, a key member of the lignin biosynthesis pathway, from Davidia endocarp. The gene named DiCCoAOMT1 has an ORF (open reading frame) of 744?bp and encodes a predicted protein of 239 amino acids. The expression of DiCCoAOMT1 is endocarp-specific and the expression levels increased along with the fruit development process. The encoding protein of DiCCoAOMT1 demonstrated a relatively high O-methyltransferase activity when using caffeic acid as a substrate in vitro . The tissue-specific CCoAOMT gene identified in this study might play a key role in specifically regulating the rapid lignification process in Davidia endocarp.