Study of structure-function relationships in the plant cell wall and modifications of the wall structure by enzyme engineering

We are proposing a structural study of the cell walls (CWs) and constituent polymers, as well as a study of enzymes involved in their synthesis, in various plant species exposed to the stress conditions, especially to the mechanical, UV radiation and xenobiotic stress. The studies will be performed both on the tissue sections and the corresponding isolated CWs, as well as on the tissue extracts. We shall study the general CW architecture, especially focusing to the cellulose and lignin organization and to the variations in composition and quantity of the phenols which are making the transversal bonds between lignin and other CW polymers. We shall study the enzymes- and free radicals- directed reactions included in the CW polymer synthesis in relation to their response to the stress. We shall make use of the engineering of enzymes involved in the key steps of the CW polymers synthesis or decomposition in order to be able to understand the enzyme structure-function relationships and the related polymers organisation in the CW assembly. At first we shall focus to the enzyme peroxidase and explore the influence of protein structure to the enzyme activity in the phenol polymerization (lignin synthesis) and decomposition of the phenol compounds such as xenobiotics and lignin. The experiments will be performed by using spectroscopy, microscopy, chromatography, electrophoresis, molecular biology methods, as well as special mathematical and statistical methods.