Identification and characterization of isoflavone reductase family members in soybean
Abstract
Soybean’s yield is threatened by Phytophthora sojae, a pathogen responsible for stem and root rot disease. Glyceollins, unique antimicrobial agents specific to soybeans in partially preventing P. sojae infection, are derived from the isoflavonoid branch of the general phenylpropanoid pathway. One pivotal enzyme exclusively involved in glyceollin synthesis in soybean is the isoflavone reductase (GmIFR), which catalyzes the 2'-hydroxydaidzein conversion to 2'-hydroxy-2,3-dihydrodaidzein as a precursor for glyceollin biosynthesis. To comprehensively identify all members of the GmIFR gene family within the soybean genome, keyword and blast protein searches were conducted, identifying 98 putative GmIFRs. Among these candidates, seven GmIFR candidates were selected for further investigation of which six were confirmed to be localized to the cytoplasm. Additionally, GmIFR candidates exhibited soluble expressions and were successfully purified. These findings provide a fundamental knowledge of GmIFR family members and their functional characterizations in the glyceollin pathway in soybean.