This award will support collaborative research between Dr. George Bruening of the University of California, Davis, and Dr. W.L. Gerlach of the Division of Plant Industry, Commonwealth Scientific and Industrial Research Organization (CSIRO), Canberra. The investigators will analyze the functions of, and evolution of genetic sequences in, the satellite RNA of the tobacco ringspot virus, which acts as a parasite on, and therefore biological control for, the ringspot virus itself. Mutations of the satellite RNA will further be studied to assess their ability to replicate, to be incorporated in, and to protect plants from the effects of other viruses. The project combines the expertise of the two investigators and their laboratories. The U.S. investigator is an expert on the proteins and nucleic acids involved in the replication of the tobacco ringspot virus RNA satellite, and has been successful in cloning separately the substrate and enzyme RNAs of this virus; the Australian investigator is an expert in the preparation of mutant satellite RNAs and transgenic plants. This research will contribute to fundamental understanding of how satellite RNAs function, and will guide future research in biologically engineered resistance to plant viruses.
