Thionins and defensins are basic, amphiphilic, cysteine-rich and low molecular weight plant defence proteins. These proteins are active against a broad range of phytopathogenic fungi, and can be potentially exploited both in terms of plant fungicides and as future human therapeutic agents. In our current research we aim to investigate the mode of binding of these proteins to model fungal lipid bilayers. We propose to carry out neutron reflectivity experiments at the solid-liquid interface using germanium crystals to provide experimental synergy with our ATR-FTIR spectroscopy studies. The findings from the NR and FTIR studies will determine quantitatively the protein-lpid interfacial layer structure and will enable the differences in the proteins' mode of action at membrane surfaces to be investigated.