Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Proceedings
Publication Acceptance Date: August 1, 2000
Publication Date: N/A
Interpretive Summary: This manuscript gives a broad overview of the design and construction of a genetic system that will prevent the spread of transgenes into the environment and protect US plant biotechnological advances. The system, called the Technology Protection System (TPS), functions by the use of a chemical to induce the formation of a germination disruption gene that only yworks during the late stages of seed maturation. The system works by the chemical induction of a gene that produces an enzyme that is capable of removing specific pieces of DNA from the genome, called CRE. We have designed TPS such that this enzyme removes a piece of DNA that separates two elements of a gene that codes for a germination disruption protein. This gene can only operate if the blocking DNA is removed. The germination disrupter gene is driven by a promoter, a sequence that dictates when a gene is on or off, that only comes on during the late stages of seed development, after the seed has filled and just prior to desiccation. Thus when the CRE gene is activated by chemical treatment of a founder seed, the germination disruption gene is formed as a result of the removal of a blocking piece of DNA. This gene does not become active until the plant has fully grown and produced seed. Because the seeds of this plant cannot germinate and the pollen from this plant carries the germination disrupter gene (all seeds derived from this pollen cannot germinate) and transgene contained within a TPS plant cannot escape. The advantages of this system for US Agriculture is also discussed.
Technical Abstract: The use of plant biotechnology for crop improvement has been hampered by two concerns: 1.The need to prevent escape of transgenes into wild species. 2. The ability to recuperate the investment in technology development. We have developed a genetic system that addresses these concerns. The system consists of three elements; a chemically inducible promoter, a site specific recombinase (CRE), and a late embryogenesis (Lea) specific promoter. A chemical seed treatment activates the CRE gene, CRE is synthesized and removes a blocking DNA sequence. This results in the joining of a Lea promoter to a protein synthesis inhibitor protein coding sequence to form an active gene. The protein synthesis inhibitor is only synthesized in the embryo and late in seed maturation and renders the seed nongerminable. Seeds from this plant can be used but cannot form the basis of a new crop. The pollen also carries the dominant protein synthesis inhibitor gene and thus the traits cannot be passed onto closely related weedy species. We are presently testing the system's efficacy in cotton and tobacco. This embodiment of the system was designed specifically for self pollinating crops, an alternate design is required for open- pollinating crops. The benefits of such a system to agriculture will be discussed.