Dr. Weissinger's graduate training was in plant breeding and molecular biology. prior to coming to NCSU, he was a Molecular Biologist with Pioneer Hi-Bred International, Inc., in Johnston, Iowa, where he was instrumental in the development of gene transfer (Transformation) technology for maize. Since joining the faculty of the Department of Crop Science at NCSU, he has worked to develop transformation technologies for pine and peanut. His laboratory works to develop transgenic crop varieties with improved agronomic performance and enhanced commodity value.

Improving Agronomic Performance

The Crop Molecular Biology Laboratory is working to produce transgenic crop varieties with enhanced resistance against pathogens. For example, we are developing transgenic tobacco lines that are highly resistant to tomato spotted wilt virus (TSWV), a pathogen which causes severe crop losses in the Southeastern United States. Transgenic tobaccos were produced by introducing into them a gene encoding the coat protein of TSWV. Plants expressing this gene exhibit excellent resistance to the virus. under severe virus pressure in field environments. We are also working to produce peanut varieties which are resistant to infection by Aspergillus flavus, a fungus which causes aflatoxin contamination. Cultured peanut tissues are transformed with genes encoding antifungal proteins using microprojectile bombardment, a procedure for delivering DNA directly into plant cells. If resistance can be achieved, severe economic losses caused by contamination with this fungus can be prevented.

Enhancing Commodity Value

We are also working to produce transgenic crop varieties which express novel high-value products that will permit growers to access new markets for their commodities. These "value-added" traits can be produced by introducing transgenes encoding valuable proteins for use in industrial processes and pharmaceutical products. For example, the Crop Molecular biology Laboratory is developing lines of tobacco that will express a protein that functions as a vaccine against human papillomaviruses, viruses that cause cervical cancer in humans. This protein can then be extracted using technology developed at NCSU and purified for injection into patients. Vaccine produced in this way will be much less expensive than vaccines produced by traditional means, which often employ living animals to generate the vaccine proteins.

Fundamental Studies in Plant Molecular Biology

In the course of carrying out the projects described above, we encounter numerous interesting questions related to the expression and long-term stability of transgenes in plants. A great concern is achieving stable transgene expression over generations in order to allow farmers to produce these improved varieties with confidence, knowing that the new gene will be expressed reliably. We are working on the use of various genetic elements, such as matrix attachment regions (MARs) to enhance expression levels and stabilize transgene expression over time. This work not only contributes to the utility of transgenic varieties, but also allows us to study the mechanisms affecting transgene performance.