The plasmid of Agrobacterium tumefaciens has been successfully inserted into protoplasts of higher plants. The fate of this plasmid, which is responsible for tumorigenicity, will be studied in protoplasts. These studies will include the determination of plasmid DNA replication, transcription, integration and gene product synthesis. Analyses will be made of the gene products by comparing them with those products synthesized in in vitro using plasmid segments carrying the genes for tumorigenicity. The biological functions of the host cells that are harboring the Agrobacterium plasmids will be scored for the expression of tumor phenotypic features. BIBLIOGRAPHIC REFERENCES: Kado, C.I. 1977. Nature of plasmids in phytopathogenic bacteria with special reference to Agrobacterium tumefaciens plasmids. In Beltsville Symposia in Agricultural Research 1. Virology in Agriculture. Allanheld, Osmun, Montclair, New Jersey, pp. 247-266. Lin, B.-C., and C. I. Kado. 1977. Evidence for the utilization of galactose by normal and transformed plant cells in culture. Botanical Bulletin of the Academia Sinica 18:71-77.