Mycogen Plant Science, Inc.

Roy C French

Paul G Ahlquist

Robert F Sacher

A +strand RNA viral transformation of host organisms with foreign RNA, and expression of said foreign RNA. The foreign RNA is inserted into an infective RNA viral segment containing replication elements, and allowed to infect the host organism. The invention is exemplified utiliing brome mosaic RNA modified to contain a gene coding for chloramphenicol acetyl transferase (CAT) in the transformation of barley protoplasts.

RNA transformation vector

A recombinant RNA virus is provided allowing encapsidation of genetically engineered viral sequences in heterologous, preferably rod-shaped coat, protein capsids. Since icosahedral viruses are limited in the amount of RNA they can carry, and rod-shaped viruses are expansible, this invention allows the size of recombinant virus RNA components to be increased (or decreased). Methods of making and using such recombinant viruses are also provided, specifically with respect to the transfection of plants to bring about genotypic and phenotypic changes.

Plasmid encoding hybrid RNA virus

A subgenomic promoter of a positive strand RNA virus is disclosed which directs the amplified expression of a structural gene in plant tissue. The core region and an upstream activating domain of the subgenomic promoter are identified. This promoter can be utilized in a modified virus, or in an appropriate engineered recombinant DNA derivative which may be chromosomally integrated or maintained as an episome in transformed cells.

Subgenomic promoter

Plant tissue comprising a subgenomic promoter

Hybrid RNA virus

A + strand RNA viral transformation of host organisms with foreign RNA, and expression of said foreign RNA. The foreign RNA is inserted into an infective RNA viral segment containing replication elements, and allowed to infect the host organism. The invention is exemplified utilizing brome mosaic RNA modified to contain a gene codting for chloramphenicol acetyl transferase (CAT) in the transformation of barley protoplasts.

A subgenomic promoter of a positive strand RNA virus is disclosed which directs the amplified expression of a structural gene in plant tissue. The core region and an upstream activating domain of the subgenomic promoter are identified. This promoter can be utilized in a modified virus, or in an appropriate engineered recombinant DNA derivative, which may be chromosomally integrated or maintained as an episome in transformed cells.

Growing community of inventors

Madison, WI, United States of America

Roy C French