We mined the soybean genome and identified over 5500 putative transcription factors (Libault et al., 2009
). A searchable database focused on the soybean TF genes was developed (http://casp.rnet.missouri.edu/soydb/
) (Wang et al., 2009
). We utilized both qRT-PCR and Illumina Solexa cDNA sequencing to identify 204 TF genes that responded directly to B. japonicum inoculation. We also showed that RNAi silencing of a specific Myb TF gene significantly reduced soybean nodulation (Libault et al., 2009).