Biological nitrification inhibition in maize—isolation and identification of hydrophobic inhibitors from root exudates

Abstract To control agronomic N losses and reduce environmental pollution, biological nitrification inhibition (BNI) is a promising strategy. BNI an ecological phenomenon by which certain plants release bioactive compounds that can suppress nitrifying soil microbes. Herein, we report on two hydrophobic released from maize root exudation ( 1 2 ), together with inside roots 3 4 ). On the basis of bioassay-guided fractionation method using recombinant bacterium Nitrosomonas europaea , 2,7-dimethoxy-1,4-naphthoquinone ED 50 = ?M) was identified for first time dichloromethane (DCM) wash concentrate surface named “zeanone.” The benzoxazinoid 2-hydroxy-4,7-dimethoxy-2 H -1,4-benzoxazin-3(4 )-one (HDMBOA, 13 isolated DCM extract roots, analogs compound 2-hydroxy-7-methoxy-2 (HMBOA, 91 HDMBOA-?-glucoside 94 ?M), were methanol roots. Their chemical structures – ) determined extensive spectroscopic methods. contributions these four to activity in 19%, 20%, 2%, 4%, respectively. A possible biosynthetic pathway zeanone proposed. These results provide insights into strength systems, identities BNIs, their relative contribution systems.