Structural Glycomic Analysis of the Plant Cell Wall

Carbohydrates, also called glycans, are the most abundant biopolymers on Earth. They are essential to all known living organisms from bacteria to humans, but their importance is perhaps most striking in plants. Plants use glycans as their main building material, encasing their cells in a rigid and complex glycan wall that is central to their growth, resistance, and intercellular communication. However, the plant cell wall is also extraordinarily complex, and the molecular structure of its many glycan constituents remains poorly understood as conventional analytical methods struggle to deal with the immense complexity of these molecules. The aim of this project is to unravel the structure of plant cell wall glycans (e.g. hemicelluloses, pectins, and arabinogalactans) through the development of novel analytical methods based on ion mobility-mass spectrometry (IM-MS). Resolving isomeric structures and identifying novel structural motifs in plant polysaccharides are key challenges to overcome for a better understanding of cell wall structures. To this end, we will develop multidimensional LC-IM-MS workflows and establish a plant glycan database building on the unique library of synthetic plant oligosaccharide standards of the Pfrengle group. The plant glycomics methods developed herein will be applied to the study of Arabidopsis thaliana mutants with cell wall defects, revealing the role of specific genes in the formation of defined structural motifs in the plant cell wall. Through offering molecular-level insight into the main structural building blocks of the cell wall, our project will facilitate our understanding of cell wall formation and the structure-function relationships that govern its various roles in plants from development to immunity.