Graduate Student University of Florida Gainesville, Florida
The cell wall is a complex matrix of polysaccharides that represent the largest source of renewable carbohydrates on Earth and recent efforts have attempted to implement them in biofuel production. Furthermore, hemicelluloses such as β-1,4-linked mannans are recognized as an important dietary fibre and have been characterized to minimize the impact of human diseases such as type II diabetes. Despite their important applications in renewable energy and human health, the complex mechanisms of the cell wall remain widely unknown. Increased knowledge of the cell wall architecture and the key enzymes that facilitate its structure and function will propel the development of more efficient, bioenergy production technologies and improved nutritional value crops.
Endo-β-mannanases (MAN) are glycosyl hydrolases responsible for the cleavage of the β-1-4-linked mannosyl bonds for cell wall remodeling as well as for carbon mobilization during seed germination. Here, we propose an alternate role of mannanases during the synthesis of mannans in Arabidopsis thaliana. Mucilage staining and ion chromatography monosaccharide analyses of Arabidopsis mutantseeds revealed that the two MAN genes are required to maintain galactoglucomannan (GGM) production. To further explore the unexpected decrease of GGM in man mutants, novelCarbohydrate-Binding fluorescent reporters will be utilized as biosensors to non-invasively track and quantify mannan content in planta. Moreover, the action of the MAN genes will be characterized (gluco)mannan-producing strains of Pichia pastoris yeast cells. Collectively, our results will provide new insights into MAN function during mannan synthesis.