Journal Article

Detection, isolation and characterization of a root-exuded compound, methyl 3-(4-hydroxyphenyl) propionate, responsible for biological nitrification inhibition by sorghum (Sorghum bicolor)

Pearse, Stuart J., Subbarao, Guntur V., Ishikawa, Takayuki, Yoshihashi, Tadashi, Gopalakrishnan, Subramaniam, Yoshida, Mitsuru, Zakir, Hossain A. K. M., Nakahara, Kazuhiko, Ono, Hiroshi, Ito, Osamu, Kawano, Naoyoshi

2008

Overview

Nitrification results in poor nitrogen (N) recovery and negative environmental impacts in most agricultural systems. Some plant species release secondary metabolites from their roots that inhibit nitrification, a phenomenon known as biological nitrification inhibition (BNI). Here, we attempt to characterize BNI in sorghum (Sorghum bicolor).• In solution culture, the effect of N nutrition and plant age was studied on BNI activity from roots. A bioluminescence assay using recombinant Nitrosomonas europaea was employed to determine the inhibitory effect of root exudates. One major active constituent was isolated by activity-guided HPLC fractionations. The structure was analysed using NMR and mass spectrometry. Properties and the 70% inhibitory concentration (IC70) of this compound were determined by in vitro assay.• Sorghum had significant BNI capacity, releasing 20 allylthiourea units (ATU) g−1 root DW d−1. Release of BNI compounds increased with growth stage and concentration of supply. -grown plants released several-fold higher BNI compounds than -grown plants. The active constituent was identified as methyl 3-(4-hydroxyphenyl) propionate.• BNI compound release from roots is a physiologically active process, stimulated by the presence of . Methyl 3-(4-hydroxyphenyl) propionate is the first compound purified from the root exudates of any species; this is an important step towards better understanding BNI in sorghum.

• Publisher: Blackwell Publishing,Oxford, UK : Blackwell Publishing Ltd,Blackwell Publishing Ltd
• Subject: biological nitrification inhibition / bioluminescence / BNI compounds / chemistry / developmental stages / environmental impact / Enzyme Inhibitors / Enzyme Inhibitors - isolation & purification / Enzyme Inhibitors - metabolism / high performance liquid chromatography / Hydroxylamine / Hydroxylamine - pharmacology / isolation & purification / mass spectrometry / metabolism / methyl 3-(4-hydroxyphenyl) propionate / Molecular Structure / Nitrification / Nitrogen / Nitrogen - metabolism / Nitrosomonas europaea / nuclear magnetic resonance spectroscopy / Nutrient solutions / pharmacology / Phenols / Phenols - chemistry / Phenols - isolation & purification / Phenols - metabolism / plant age / Plant collections / Plant Exudates / plant nutrition / Plant Roots / Plant Roots - chemistry / Plant Roots - metabolism / Plants / Propionates / Propionates - chemistry / Propionates - isolation & purification / Propionates - metabolism / Root exudates / roots / secondary metabolites / Sorghum / sorghum (Sorghum bicolor) / Sorghum - chemistry / Sorghum - metabolism / Sorghum bicolor