Background

There are proven health-related benefits of naturally occurring compounds in plants which have potential to reduce the risk of chronic diseases. High priority: Identification and characterization of these compounds, termed nutriceuticals or phytonnutrients.

Epidemiological evidence suggest that consumption of soy products reduces susceptibility to certain types of cancers, i.e., breast, prostate and colon cancer.

Among the many phytonutrients in soy, genistein has been demonstrated to have a specifically protective effect against cancer and cardiovascular disease. Influence of genistein on reducing breast cancer risk is due to the anti-estrogenic activity of this isoflavone.

Maize does not synthesize isoflavones, including genistein. All the lenzymes necessary for isoflavone biosynthesis are present in maize, except isoflavone synthase. Suggested is that the introduction of the gene(s) for isoflavone synthase should confer on maize the ability to produce genistein.

Discussion

The overall objective of the research is to improve the health of consumers through adding nutritional value to a well established and economically important agricultural product.

Limited understanding of the mechanisms and potential role of genistein in breast tissue exists. Therefore, a critical component of the project is to examine the influence of genistein on breast tumor development in animal models.

Proposed is to identify and clone the isoflavone synthase gene(s) from soybean and develop transgenic maize which expresses it so as to cause maize to synthesize and accumulate genistein.

Genetic manipulation of maize to produce genistein would provide consumers with the benefits derived from soy phytonutrients without the need to make dramatic changes in their eating habits.