Portland, Oregon
January 30, 2003

Scientists at Exelixis Plant Sciences, through its Agrinomics LLC joint venture with Bayer CropScience AG, have identified several new genes that confer resistance to fungal pathogens. This research has provided novel insights that will allow the development of technologies for improved plant productivity. "These new gene discoveries provide approaches for the direct engineering of fungal resistance in crop plants, as well as important tools for crop breeding," said Georges Freyssinet, a Member of the Agrinomics Board of Managers and Scientific Advisor at Bayer CropScience AG. "Clearly, there is a need for new mechanisms of providing resistance to fungal pathogens, including the development of new crop varieties."

"While there is further research involved in bringing our discoveries to crop plants, these exciting discoveries are among our first to reveal novel mechanisms for controlling major diseases of important crops," added Ry Wagner, chief scientific officer, Agrinomics, and vice president, research, Exelixis Plant Sciences.

Agrinomics, LLC has used the rapid screening and analysis of its Arabidopsis thaliana ACTTAG(TM) collection for commercially valuable traits. ACTTAG(TM) is a positive selection platform that supports high throughput discovery of genes controlling plant traits. One project has targeted the identification of novel dominant genetic mechanisms by which plants resist infection by fungal pathogens. Fungal pathogens impose greater costs upon food growers than any other plant diseases like bacterial or viral diseases. The global fungicide market was more than US $6.0 billion in 2001.

Agrinomics, LLC, formed in 1999, conducts research, development and commercialization programs in the field of agricultural functional genomics. The company is a joint venture between Exelixis Plant Sciences -- a wholly owned subsidiary of Exelixis, Inc. (Nasdaq: EXEL) -- and Bayer CropScience AG,
has as its mission to identify, develop and commercialize novel traits using the Arabidopsis ACTTAG(TM) Gene Discovery Program. Agrinomics recently entered into an agreement with Renessen LLC to develop seeds with higher oil content in corn and other crops based on traits identified under the ACTTAG Gene Discovery Program.