Deciphering Molecular Mechanisms of Lignin Precursor Transportation

Suny At Stony Brook, Stony Brook NY

Investigators

Abstract

Intellectual Merit Lignin, the second most abundant terrestrial biopolymer after cellulose, is essential for the viability of vascular plants. However, its presence in the cell wall constitutes a formidable obstacle in chemical pulping to produce fine paper, for digesting the forage crops fed to ruminants, and for producing renewable biofuels from cellulosic biomass. The biosynthesis of monolignols, the precursors to lignin, occurs in the cytosol, i.e., the intracellular fluid present in plant cells. Thereafter, these monomeric precursors are exported into the cell wall, where they are polymerized and integrated into the wall?s matrix. Accordingly, the transport of monolignols across the cell membrane is a critical step affecting the deposition of lignin in the secondarily thickened cell wall. While the biosynthesis of monolignols is relatively well understood, the knowledge on the molecular basis for sequestering and transporting those lignin monomers is largely unknown. The aims of this project are the following: 1) through biochemical studies in gymnosperms and in angiosperms, to explore and clarify the molecular mechanisms underlying the subcellular sequestration and transport of lignin monomers across the plasma membranes; and, 2) to identify and characterize the particular membrane transporters involved in lignin deposition during the formation of secondary cell walls. Broader Impacts This project focuses on one of the most critical, yet least studied, metabolic steps in plant lignification. The knowledge gained from it will further the understanding of lignin biosynthesis, and very likely support a better biotechnological solution to efficiently manipulate the lignification process, thereby enhancing the agricultural and industrial applications of cell wall biomaterials. This project also contains a substantial educational component that involves the training of young scientists as the central focus. In addition to training postdoctoral research scientists, graduate students, and technicians, the project will encompass a vigorous program aimed at teaching science at junior levels. High-school students, along with minority undergraduates will be recruited from Stony Brook and local colleges through summer internships and academic year collaborations, and will be introduced to the ways of conducting scientific research. This experience will help students solidify their interest in pursuing a career in science; it also represents a valuable outreach activity to the scientific community.