TY  - JOUR
A1  - Wang, Wei-Hong
A1  - Köhler, Barbara
A1  - Cao, Feng-Qiu
A1  - Liu, Guo-Wei
A1  - Gong, Yuan-Yong
A1  - Sheng, Song
A1  - Song, Qi-Chao
A1  - Cheng, Xiao-Yuan
A1  - Garnett, Trevor
A1  - Okamoto, Mamoru
A1  - Qin, Rui
A1  - Müller-Röber, Bernd
A1  - Tester, Mark
A1  - Liu, Lai-Hua
T1  - Rice DUR3 mediates high-affinity urea transport and plays an effective role in improvement of urea acquisition and utilization when expressed in Arabidopsis
JF  - New phytologist : international journal of plant science
N2  - 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 mu M) 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 mu M 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.
KW  - high-affinity transporter
KW  - leaf senescence
KW  - nitrogen remobilization
KW  - OsDUR3
KW  - overexpression
KW  - rice plant
KW  - urea transport and utilization
Y1  - 2012
U6  - https://doi.org/10.1111/j.1469-8137.2011.03929.x
SN  - 0028-646X
VL  - 193
IS  - 2
SP  - 432
EP  - 444
PB  - Wiley-Blackwell
CY  - Malden
ER  - 
TY  - JOUR
A1  - Balazadeh, Salma
A1  - Kwasniewski, Miroslaw
A1  - Caldana, Camila
A1  - Mehrnia, Mohammad
A1  - Zanor, Maria Ines
A1  - Xue, Gang-Ping
A1  - Müller-Röber, Bernd
T1  - ORS1, an H2O2-Responsive NAC Transcription Factor, Controls Senescence in Arabidopsis thaliana
JF  - Molecular plant
N2  - We report here that ORS1, a previously uncharacterized member of the NAC transcription factor family, controls leaf senescence in Arabidopsis thaliana. Overexpression of ORS1 accelerates senescence in transgenic plants, whereas its inhibition delays it. Genes acting downstream of ORS1 were identified by global expression analysis using transgenic plants producing dexamethasone-inducible ORS1-GR fusion protein. Of the 42 up-regulated genes, 30 (similar to 70%) were previously shown to be up-regulated during age-dependent senescence. We also observed that 32 (similar to 76%) of the ORS1-dependent genes were induced by long-term (4 d), but not short-term (6 h) salinity stress (150 mM NaCl). Furthermore, expression of 16 and 24 genes, respectively, was induced after 1 and 5 h of treatment with hydrogen peroxide (H2O2), a reactive oxygen species known to accumulate during salinity stress. ORS1 itself was found to be rapidly and strongly induced by H2O2 treatment in both leaves and roots. Using in vitro binding site selection, we determined the preferred binding motif of ORS1 and found it to be present in half of the ORS1-dependent genes. ORS1 is a paralog of ORE1/ANAC092/AtNAC2, a previously reported regulator of leaf senescence. Phylogenetic footprinting revealed evolutionary conservation of the ORS1 and ORE1 promoter sequences in different Brassicaceae species, indicating strong positive selection acting on both genes. We conclude that ORS1, similarly to ORE1, triggers expression of senescence-associated genes through a regulatory network that may involve cross-talk with salt- and H2O2-dependent signaling pathways.
KW  - NAC transcription factor
KW  - leaf senescence
KW  - gene expression
KW  - gene regulatory network
KW  - hydrogen peroxide
Y1  - 2011
U6  - https://doi.org/10.1093/mp/ssq080
SN  - 1674-2052
VL  - 4
IS  - 2
SP  - 346
EP  - 360
PB  - Oxford Univ. Press
CY  - Oxford
ER  -