As one of the most important seed crops in the world, an understanding of the regulatory networks that shape the biochemical properties of soybean seed are becoming increasingly important. Virus induced gene silencing (VIGS) is a powerful tool for functional genomics that permits inactivation of individual genes or closely related gene families. Inactivation of genes through VIGS is most effective in cells where recombinant viruses replicate. Tobacco streak virus (TSV), a virus that commonly infects soybean, readily invades meristematic tissues and developing soybean embryos, which results in high rates of seed transmission (often >50%). Consequently, VIGS vectors based on TSV would permit...