Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis.
• 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 (K(m) 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 K(m) 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.
Department of Plant Nutrition, Key Laboratory of Plant and Soil Interactions of MEoC, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.
Wei-Hong
WH
Wang
Barbara
B
Köhler
Feng-Qiu
FQ
Cao
Guo-Wei
GW
Liu
Yuan-Yong
YY
Gong
Song
S
Sheng
Qi-Chao
QC
Song
Xiao-Yuan
XY
Cheng
Trevor
T
Garnett
Mamoru
M
Okamoto
Rui
R
Qin
Bernd
B
Mueller-Roeber
Mark
M
Tester
Lai-Hua
LH
Liu
D000818:Animals; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009584:Nitrogen / Q000378:metabolism; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D012275:Oryza / Q000187:drug effects / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000187:drug effects / Q000378:metabolism; D030821:Plants, Genetically Modified; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014508:Urea / Q000378:metabolism* / Q000494:pharmacology; D014982:Xenopus laevis; D000096982:Urea Transporters
D049452:Green Fluorescent Proteins; D026901:Membrane Transport Proteins; D009584:Nitrogen; D010940:Plant Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D014508:Urea; D000096982:Urea Transporters