Planting the Chalcone Reductase Family Tree: Identification and Characterization of Chalcone Reductase Genes in Soybean

Soybean (Glycine max [L.] Merr) is an important crop grown in Canada, generating $2.4 billion in sales. Though this number may be promising, soybean farmers lose about $50 million worth of yield annually due to root and stem rot disease caused by Phytophthora sojae. Many strategies have been developed to combat the infection; however, these methods are prohibitively expensive. A ‘cost effective’ approach to this problem is to select a trait naturally found in soybean that can increase resistance. One such trait is the increased production of root glyceollins. One of the key enzymes exclusively involved in glyceollin synthesis is chalcone reductase (CHR). To identify all GmCHR gene family members in the soybean genome, a search was conducted in Phytozome which revealed 16 putative GmCHRs. Among these, 7 GmCHRs were selected for further study as they contain all active site residues, and are transcribed. All candidate GmCHRs localize to both the nucleus and cytoplasm. Amongst the candidate GmCHRs, there are four root-specific GmCHRs which are induced upon stress. In addition, three QTLs have been found which contain GmCHR loci. Overall, these findings suggest that chalcone reductase is an important component in manipulating glyceollin content and could eventually be used to improve resistance against P. sojae