The author confirms that the work submitted is his own, expect where work, which has formed a part of jointly-authored publications has been included. The contribution of the candidate and other authors to this work has been explicitly indicated below. The author also confirms that appropriate credit has been given within this thesis where reference has been made to the work of others.

In Chapter 4, liverworts were grown and maintained by Ms Bev Merry. The initial ELISA screen on liverwort agar gel extracts, and liverwort imaging and tissue printing was performed by Ms Sue Marcus. This contributed to Figure 4.15.

In Chapter 4, work leading to the monosaccharide composition and monosaccharide linkage analyses included in Tables 4.1 and 4.2, and Figures 4.16 and 1.7 was undertaken by Mr Bernhard Jaehrig based at the Complex Carbohydrate Research Centre, US. Data was analysed and summarised by the candidate.