Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis
Article first published online: 19 OCT 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 193, Issue 2, pages 432–444, January 2012
How to Cite
Wang, W.-H., Köhler, B., Cao, F.-Q., Liu, G.-W., Gong, Y.-Y., Sheng, S., Song, Q.-C., Cheng, X.-Y., Garnett, T., Okamoto, M., Qin, R., Mueller-Roeber, B., Tester, M. and Liu, L.-H. (2012), Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis. New Phytologist, 193: 432–444. doi: 10.1111/j.1469-8137.2011.03929.x
- Issue published online: 20 DEC 2011
- Article first published online: 19 OCT 2011
- Received: 19 July 2011, Accepted: 5 September 2011
- high-affinity transporter;
- leaf senescence;
- nitrogen remobilization;
- rice plant;
- urea transport and utilization
- •Despite the great agricultural and ecological importance of efficient use of urea-containing nitrogen fertilizers by crops, molecular and physiological identities of urea transport in higher plants have been investigated only in Arabidopsis.
- •We performed short-time urea-influx assays which have identified a low-affinity and high-affinity (Km of 7.55 μM) transport system for urea-uptake by rice roots (Oryza sativa).
- •A high-affinity urea transporter OsDUR3 from rice was functionally characterized here for the first time among crops. OsDUR3 encodes an integral membrane-protein with 721 amino acid residues and 15 predicted transmembrane domains. Heterologous expression demonstrated that OsDUR3 restored yeast dur3-mutant growth on urea and facilitated urea import with a Km of c. 10 μM in Xenopus oocytes.
- •Quantitative reverse-transcription polymerase chain reaction (qPCR) analysis revealed upregulation of OsDUR3 in rice roots under nitrogen-deficiency and urea-resupply after nitrogen-starvation. Importantly, overexpression of OsDUR3 complemented the Arabidopsis atdur3-1 mutant, improving growth on low urea and increasing root urea-uptake markedly. Together with its plasma membrane localization detected by green fluorescent protein (GFP)-tagging and with findings that disruption of OsDUR3 by T-DNA reduces rice growth on urea and urea uptake, we suggest that OsDUR3 is an active urea transporter that plays a significant role in effective urea acquisition and utilisation in rice.