Potential Secretory Transporters and Biosynthetic Precursors of Biological Nitrification Inhibitor 1,9-Decanediol in Rice as Revealed by Transcriptome and Metabolome Analyses
Di Dongwei, MA Ming-kun, Zhang Xiaoyang, LU Yufang, Herbert J. Kronzucker, Shi Weiming
Abstract
Biological nitrification inhibitors (BNIs) are released from plant roots and inhibit the nitrification activity of microorganisms in soils, reducing NO3‒ leaching and N2O emissions, and increasing nitrogen-use efficiency (NUE). Several recent studies have focused on the identification of new BNIs, while little is known about the genetic loci governing their biosynthesis and secretion. We applied a combined transcriptomic and metabolomic analysis to investigate possible biosynthetic pathways and transporters implicated in the biosynthesis and release of BNI 1,9-decanediol (1,9-D), previously identified in rice root exudates. Our results link four fatty acids, icosapentaenoic acid, linoleate, norlinolenic acid, and polyhydroxy-α,ω-divarboxylic acid, to 1,9-D biosynthesis, and three transporter families, namely the ATP-binding cassette protein family, the multidrug and toxic compound extrusion family, and the major facilitator superfamily, to 1,9-D release from roots into the soil medium. Our results provide candidates for further work on the genes implicated in the biosynthesis and secretion of 1,9-D and pinpoint genetic loci for crop breeding to improve NUE by enhancing 1,9-D secretion, with the promise of reducing NO3‒ leaching and N2O emissions from agricultural soils.