This Small Business Innovation Research (SBIR) Phase I research project will use a new proprietary technology, host-mediated silencing (inhibition) of pathogen genes (HMSPG), to develop soybeans that resistant to single and multiple fungal diseases. The primary objective is to develop plants resistant to soybean rust, the most serious disease of soybeans in the world. Soybean rust now poses a major threat to domestic soybean production. HMSPG exploits the plants RNA interference (RNAi) mechanism to inhibit expression of essential pathogen genes creating a disease resistant plant. Soybeans resistant to soybean rust will enable production security for soybean growers and food security for domestic and international consumers of U.S. soybean products, as well as reduce the application of millions of tons of fungicides annually. A unique capability of HMSPG is to stack fungal resistance genes to simultaneously develop plants resistant to more than one disease. The second research objective is to develop plants resistant to both soybean rust and to soybean stem and root rot. Soybeans resistant to both diseases will further reduce fungicide applications, reduce development of pathogen resistance to the fungicides and reduce development of new races of these pathogens.
Commercially, the application is develop soybean plants resistant to soybean rust that would decrease agricultural losses due to that disease. Resistance to multiple pathogens would prevent even greater crop losses, increasing the market value of these resistant soybean seeds. The U.S. is the worlds largest producer and exporter of soybeans, a major world food crop. In 2004 the value of the U.S. soybean crop was $17.7 billion. The U.S. accounted for 40% of the worlds soybean production, and for 48 percent of the world's soybean trade, valued at $8 billion. A significant decrease in soybean production would adversely impact both exports and U.S. livestock production, which uses soybean extensively for feed. Fungal diseases such as soybean rust and soybean stem and root rot cause major losses in soybean production; up to 90% for SR and 11% for SSRR. Both diseases are major pathogens in the United States. Loss of 10% of the U.S. soybean crop would cost $1.7 billion, and spraying one-half of the U.S. acreage once with fungicide would cost $1 billion; a total annual cost of $2.7 billion.
