Despite the importance of seed yield and composition in determining crop value, little is known about the genes responsible for controlling these traits. In previous research we determined that the SIS8 gene from the model oilseed plant Arabidopsis thaliana is a strong candidate to play an important role in regulating seed yield and composition. A field trial in Saint Paul showed that seven SIS8 transgenic soybean lines produced yields that were 117-153% of the yield of the non-transgenic control line. Four SIS8 transgenic lines also had statistically significant increases in either seed oil or protein contents. The specific objectives of this proposal are to characterize the mechanism by...