9407177 McDonald This project is to advance and broaden our knowledge in the areas of plant cell biotechnology, ribosome inactivating proteins (RIPs), and plant cell bioprocess engineering. This project has three specific goals, which include: (1) characterization of the transformation of plant cell cultures by the plant pathogen Agrobacterium rhizogenes; (2) quantification of cell growth and RIP production in suspension culture; and (3) purification and characterization of proteins obtained from the cell cultures. RIPs are naturally occurring plant proteins thought to be ubiquitous in the plant kingdom, and are currently receiving considerable attention for their antiviral, antitumor and abortifacient properties. They are also being considered for their potential use in immunotoxin preparation and for their ability to confer resistance to plant pathogens. ***