Research objectives and content
The texture (and hence quality) of vegetables and fruits is influenced strongly by the mechanical properties of the plant cell wall. Although there is considerable knowledge of the structures of cell wall polymers and of the mechanical properties of cell walls and tissues, a major and persistent problem is a lack of knowledge of how altered molecular structures within cell walls translate into changes in mechanical properties.
My doctoral work in Spain has focused on the role of the cell wall associated peroxidases in the stiffening of the cell wall during growth. It would greatly enhance my future research potential if I were to gain experience in the major polysaccharide networks of cell walls, and at the same time acquire experience in molecular biology. I would therefore like to join of Professor J S Grant Reid's laboratory to participate in an investigation of the effect of xyloglucan structure modification on the properties of xyloglucan-cellulose networks.
The objectives of the work I propose in Professor Reid's laboratory are (1) to purify a xyloglucan-active a-L-fucosidase from germinated nasturtium seeds in quantities sufficient to allow its use to modify xyloglucan structure in vitro on a hundreds-of milligrams scale (2) to prepare fucose-modified xyloglucans to be assessed, in collaboration with Industry, in novel cell wall like in vitro-assembled cellulose-xyloglucan networks and (3) to obtain a cDNA clone of the fucosidase with a view to future overexpression of the enzyme.
Training content (objective, benefit and expected impact)
Professor Reid's laboratory at U Stirling enjoys world status in the isolation and molecular characterization of natural plan enzymes capable of modifying the important cellulose-xyloglucan network of the plant cell wall. By joining this active group shall learn plant enzymology and molecular biology in the context described above. and also gain exposure to their highly specialized systems to study plant cell wall polysaccharide biosynthesis.
Links with industry / industrial relevance (22)
The team collaborates closely, on an "open laboratory" basis with the industrial laboratories of Unilever plc, a major European food industry, at Bedford. I shall have the opportunity of visiting the Unilever laboratories, gaining exposure to the xyloglucan network model, to state of the an methodologies to measure cell wall rheology, and to an array of physicochemical method applied to plant cell walls.