Transcriptional Regulation of Secondary Wall Biosynthesis

University Of Georgia Research Foundation Inc, Athens GA

Investigators

Abstract

The objective of the project is to investigate the transcriptional network regulating secondary wall biosynthesis in plants. Secondary walls are the major constituent of tracheary elements and fibers in wood, which is the most abundant biomass produced by plants and is widely used for pulping, paper-making, and many other commodities. To make secondary walls, genes involved in the biosynthesis of secondary wall components, including cellulose, hemicellulose and lignin, need to be coordinately turned on. Therefore, it is conceivable that there exist genetic switches responsible for turning on the secondary wall biosynthetic program. Currently, little is known about the molecular mechanisms underlying the regulation of secondary wall biosynthesis during wood formation. The investigators have recently discovered that the secondary wall-associated NAC domain transcription factor SND1 is a key switch in activating the developmental program of secondary wall biosynthesis, and that SND1 regulates the expression of several other secondary wall-associated transcription factors. One of them, MYB46, was demonstrated to be a direct target of SND1, and act upstream of the transcription factors MYB85 and KNAT7 in the regulation of secondary wall biosynthesis. Based on these findings, the investigators hypothesize that a hierarchy of transcriptional factors is involved in the regulation of secondary wall biosynthesis, and plan to unravel the SND1-mediated transcriptional network by functional characterization of the secondary wall-associated, SND1-regulated transcription factors and dissection of their interrelationships in the network. Broader impacts. The results from this project will contribute to our understanding of the molecular mechanisms underlying wood formation, and the knowledge gained will potentially provide valuable tools for genetically improving the quality and quantity of wood, the most important raw materials for traditional forest products and potentially for biofuel production. The investigators will actively integrate the proposed research with teaching activities and training of graduate and undergraduate students, especially from underrepresented groups, and will make every effort to disseminate the results of the project to enhance the understanding of plant biology research and its benefits to the society.