The molecular mechanism in secondary wall deposition and programmed cell death of wood formation

Abstract

Wood formation occurs through continuous steps involving cambium cell proliferation, xylem cell specification and expansion, secondary wall deposition and programmed cell death (PCD). Recently, many key transcription factors/repressors and enzymes involved in secondary wall formation and PCD processes have been identified based on genetics and omics analysis in model plants Arabidopsis and poplar. All these hierarchical transcription factors build the transcriptional regulatory network of secondary wall deposition. These transcription factors not only play important role in regulating the biosynthesis of secondary wall components including lignin, cellulose and xylan, but also activate downstream hydrolytic enzymes and trigger PCD process. To analyze the biological function and regulatory network of these genes, it will provide the theoretical foundation for elucidating the molecular mechanism of wood formation. In this paper, we review the advances of transcriptional regulatory network in secondary wall deposition and enzymatic mechanism in PCD of wood formation.