This award supports Professor Jozef J. Bujarski for cooperative research with Profesor Jerzy Paszkowski of the Institute of Plant Sciences, Swiss Federal Institute of Technology, Zurich. They are collaborating in developing a process for amplifying selected gene transcripts in plant tissues so that large amounts of particular gene products will be produced. Their novel approach is to use replicases of plant RNA viruses for replication of other mRNAs. Their goal is to produce model systems to investigate virus replication and interaction of replicase with host proteins. The proposed research requires expertise in two different areas: the molecular biology of plant viruses and plant tissue culture. Dr. Bujarski is an expert in the molecular biology of bromoviruses and the mechanisms involved in the replication of their genomes. The Swiss lab is a world leader in direct gene transfer, and Dr. Paszkowski has substantial experience in the transformation and regeneration of plants, especially tobacco. The molecular cloning will be done primarily in the U.S. lab, and transformation of protoplasts and regeneration of transgenic plants will be done in Switzerland. The joining of critical complementary expertise will bring substantial mutual benefits to the two research groups. The long term goal of this research is to understand molecular mechanisms of expression and function of genes in plant cells. This should make it possible to selectively amplify or inhibit the expression of desired genes in plant cells. One of the major problems of expression of genes in transgenic plants is obtaining sufficient levels of mRNA. If this novel approach is successful as a way to amplify messages in a bromovirus/tobacco system, it will be of great utility for virtually all applications of transgenic plants and basic virology research and will greatly assist the development of virus-based tools in plant genetic engineering.