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Score: 4.00 |
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| Title: Understanding the differential nitrogen sensing mechanism in rice genotypes through expression analysis of high and low affinity ammonium transporter genes .
| | Author: Gaur VS Singh US Gupta AK Kumar A | | Journal: Mol Biol Rep Citation: V : 39 P : 2233-41 Year: 2012 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub21678052 Accession (PMID): 21678052 | | Abstract: Two rice genotypes , Kalanamak 3119 ( KN3119 ) and Pusa Basmati 1 ( PB1 ) differing in their optimum nitrogen requirements ( 30 and 120 kg/ha , respectively ) were undertaken to study the expression of both high and low affinity ammonium transporter genes responsible for ammonium uptake .
Exposing the roots of the seedlings of both the genotypes to increasing ( NH ( 4 ) ) ( 2 ) SO ( 4 ) concentrations revealed that all the three families of rice AMT genes are expressed , some of which get altered in a genotype and concentration specific manner .
This indicates that individual ammonium transporter genes have defined contributions for ammonium uptake and plant growth .
Interestingly , in response to increasing nitrogen concentrations , a root specific high affinity gene , AMT1 ; 3 , was repressed in the roots of KN3119 but not in PB1 indicating the existence of a differential ammonium sensing mechanism .
This also indicates that not only AMT1 ; 3 is involved not only in ammonium uptake but may also in ammonium sensing .
Further , if it can differentiate and could be used as a biomarker for nitrogen responsiveness .
Expression analysis of low affinity AMT genes showed that , both AMT2 ; 1 and AMT2 ; 2 have high levels of expression in both roots and shoots and in KN3119 are induced at low ammonium concentrations .
Expressions of AMT3 family genes were higher shoots than in the roots indicating that these genes are probably involved in the translocation and distribution of ammonium ions in leaves .
The expression of the only high affinity AMT gene , AMT1 ; 1 , along with six low affinity AMT genes in the shoots suggests that low affinity AMTs in the shoots leaves are involved in supporting AMT1 ; 1 to carry out its activities/function efficiently .
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[ Sen. 9, subscore: 2.00 ]: The expression of the only high affinity AMT gene , AMT1 ; 1 , along with six low affinity AMT genes in the shoots suggests that low affinity AMTs in the shoots leaves are involved in supporting AMT1 ; 1 to carry out its activities/function efficiently .
[ Sen. 4, subscore: 1.00 ]: Interestingly , in response to increasing nitrogen concentrations , a root specific high affinity gene , AMT1 ; 3 , was repressed in the roots of KN3119 but not in PB1 indicating the existence of a differential ammonium sensing mechanism .
[ Sen. 5, subscore: 1.00 ]: This also indicates that not only AMT1 ; 3 is involved not only in ammonium uptake but may also in ammonium sensing .
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Score: 2.00 |
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| Title: Distinct expression and function of three ammonium transporter genes ( OsAMT1 ; 1-1 ; 3 ) in rice .
| | Author: Sonoda Y Ikeda A Saiki S von Wirn N Yamaya T Yamaguchi J | | Journal: Plant Cell Physiol .
Citation: V : 44 ( 7 ) P : 726-34 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12881500 Accession (PMID): 12881500 | | Abstract: To study the regulation of ammonium uptake into rice roots , three ammonium transporter genes ( OsAMT1 ; 1 , 1 ; 2 and 1 ; 3 ; Oryza sativa ammonium transporter ) were isolated and examined .
OsAMT1s belong to AMT1 family , containing 11 putative transmembrane-spanning domains .
Southern blot analysis and screening of the rice genome database confirmed that with OsAMT1 ; 1-1 ; 3 the complete AMT1 family of rice had been isolated .
Heterologous expression of OsAMT1s in the yeast Saccharomyces cerevisiae mutant 31019b showed that all three OsAMT1s exhibit ammonium transport activity .
Northern blot analysis showed a distinct expression pattern for the three genes ; more constitutive expression in shoots and roots for OsAMT1 ; 1 , root-specific and ammonium-inducible expression for OsAMT1 ; 2 , and root-specific and nitrogen-derepressible expression for OsAMT1 ; 3 .
In situ mRNA detection revealed that OsAMT1 ; 2 is expressed in the central cylinder and cell surface of root tips .
This gene expression analysis revealed a distinct nitrogen-dependent regulation for AMTs in rice , differing from that in tomato or ARABIDOPSIS : | Matching Sentences:
[ Sen. 2, subscore: 1.00 ]: OsAMT1s belong to AMT1 family , containing 11 putative transmembrane-spanning domains .
[ Sen. 3, subscore: 1.00 ]: Southern blot analysis and screening of the rice genome database confirmed that with OsAMT1 ; 1-1 ; 3 the complete AMT1 family of rice had been isolated .
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Score: 2.00 |
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| Title: A proteomic and phosphoproteomic analysis of Oryza sativa plasma membrane and vacuolar membrane .
| | Author: Whiteman SA Nuhse TS Ashford DA Sanders D Maathuis FJ | | Journal: Plant J Citation: V : P : Year: 2008 Type: Publisher | | Literature: oryza Field: abstract Doc ID: pub18557835 Accession (PMID): 18557835 | | Abstract: Proteomic and phosphoproteomic analyses of rice shoot and root tonoplast-enriched and plasma membrane-enriched membrane fractions were carried out to look at it issue-specific expression , and to identify putative regulatory sites of membrane transport proteins .
Around 90 unique membrane proteins were identified , which included primary and secondary transporters , ion channels and aquaporins .
Primary H ( + ) pumps from the AHA family showed little isoform specificity in their it issue expression pattern , whereas specific isoforms of the Ca ( 2+ ) pump ECA/ACA family were expressed in root and shoot it issues .
Several ABC transporters were detected , particularly from the MDR and PDR subfamilies , which often showed expression in either roots or shoots .
Ammonium transporters were expressed in root , but not shoot , it issue .
Large numbers of sugar transporters were expressed , particularly in green it issue .
The occurrence of phosphorylation sites in rice transporters such as AMT1 ; 1 and PIP2 ; 6 agrees with those previously described in other species , pointing to conserved regulatory mechanisms .
New phosphosites were found in many transporters , including H ( + ) pumps and H ( + ) : cation antiporters , often at residues that are well conserved across gene families .
Comparison of root and shoot it issue showed that phosphorylation of AMT1 ; 1 and several further transporters may be it issue dependent .
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[ Sen. 7, subscore: 1.00 ]: The occurrence of phosphorylation sites in rice transporters such as AMT1 ; 1 and PIP2 ; 6 agrees with those previously described in other species , pointing to conserved regulatory mechanisms .
[ Sen. 9, subscore: 1.00 ]: Comparison of root and shoot it issue showed that phosphorylation of AMT1 ; 1 and several further transporters may be it issue dependent .
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Score: 1.00 |
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| Title: Differential expression of three members of the AMT1 gene family encoding putative high-affinity NH4+ transporters in roots of Oryza sativa subspecies indica .
| | Author: Kumar A Silim SN Okamoto M Siddiqi MY Glass AD .
| | Journal: Citation: V : 26 ( 6 ) P : 907-914 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12803618 Accession (PMID): 12803618 | | Abstract: In order to investigate the molecular basis of high-affinity ammonium absorption by roots of rice plants ( Oryza sativa subspecies indica ) the expression patterns of three members of the AMT1 family of genes in rice seedling roots in response to altered nitrogen provision and diurnal changes in irradiance were examined .
The 13NH4+ influx and transcript levels of OsAMT1 . 1 in roots decreased several fold within 48 h when plants acclimated to 10 micro m external NH4+ for 3 weeks were transferred to 10 mm NH4+ .
Likewise when plants acclimated in 10 mm NH4+ were transferred to 10 micro m NH4+ , there was an equally rapid up-regulation of OsAMT1 . 1 and 13NH4+ influx in the roots .
Changes in transcript abundance of OsAMT1 . 2 following these treatments were approximately 50% less than in OsAMT1 . 1 , and changes of OsAMT1 . 3 expression were even less .
By contrast , in response to the diurnal changes of irradiance , root transcript abundance of OsAMT1 . 3 and 15NH4+ influx increased approximately three-fold late in the photoperiod , whereas OsAMT1 . 1 and OsAMT1 . 2 exhibited only modest changes .
The present results suggest that high-affinity NH4+ influx is differentially regulated at the transcriptional level through the expression of three members of the OsAMT1 family of genes in roots of rice seedlings in response to changes of N status and daily irradiance .
In general , these findings are in agreement with earlier observations in Arabidopsis and tomato . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: In order to investigate the molecular basis of high-affinity ammonium absorption by roots of rice plants ( Oryza sativa subspecies indica ) the expression patterns of three members of the AMT1 family of genes in rice seedling roots in response to altered nitrogen provision and diurnal changes in irradiance were examined .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Ammonium and urea transporter inventory of the selaginella and physcomitrella genomes .
| | Author: De Michele R Loque D Lalonde S Frommer WB | | Journal: Front Plant Sci Citation: V : 3 P : 62 Year: 2012 Type: In-Data-Review | | Literature: oryza Field: abstract Doc ID: pub22639655 Accession (PMID): 22639655 | | Abstract: Ammonium and urea are important nitrogen sources for autotrophic organisms .
Plant genomes encode several families of specific transporters for these molecules , plus other uptake mechanisms such as aquaporins and ABC transporters .
Selaginella and Physcomitrella are representatives of lycophytes and bryophytes , respectively , and the recent completion of their genome sequences provided us with an opportunity for comparative genome studies , with special emphasis on the adaptive processes that accompanied the conquest of dry land and the evolution of a vascular system .
Our phylogenetic analysis revealed that the number of genes encoding urea transporters underwent a progressive reduction during evolution , eventually down to a single copy in vascular plants .
Conversely , no clear evolutionary pattern was found for ammonium transporters , and their number and distribution in families varies between species .
In particular Selaginella , similar to rice , favors the AMT2/MEP family of ammonium transporters over the plant-specific AMT1 type .
In comparison , Physcomitrella presents several members belonging to both families .
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[ Sen. 6, subscore: 1.00 ]: In particular Selaginella , similar to rice , favors the AMT2/MEP family of ammonium transporters over the plant-specific AMT1 type .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Differential expression of three members of the AMT1 gene family encoding putative high-affinity NH4+ transporters in roots of Oryza sativa subspecies indica .
| | Author: Kumar A Silim SN Okamoto M Siddiqi MY Glass AD .
| | Journal: Citation: V : 26 ( 6 ) P : 907-914 Year: 2003 Type: ARTICLE | | Literature: oryza Field: title Doc ID: pub12803618 Accession (PMID): 12803618 | | Abstract: In order to investigate the molecular basis of high-affinity ammonium absorption by roots of rice plants ( Oryza sativa subspecies indica ) the expression patterns of three members of the AMT1 family of genes in rice seedling roots in response to altered nitrogen provision and diurnal changes in irradiance were examined .
The 13NH4+ influx and transcript levels of OsAMT1 . 1 in roots decreased several fold within 48 h when plants acclimated to 10 micro m external NH4+ for 3 weeks were transferred to 10 mm NH4+ .
Likewise when plants acclimated in 10 mm NH4+ were transferred to 10 micro m NH4+ , there was an equally rapid up-regulation of OsAMT1 . 1 and 13NH4+ influx in the roots .
Changes in transcript abundance of OsAMT1 . 2 following these treatments were approximately 50% less than in OsAMT1 . 1 , and changes of OsAMT1 . 3 expression were even less .
By contrast , in response to the diurnal changes of irradiance , root transcript abundance of OsAMT1 . 3 and 15NH4+ influx increased approximately three-fold late in the photoperiod , whereas OsAMT1 . 1 and OsAMT1 . 2 exhibited only modest changes .
The present results suggest that high-affinity NH4+ influx is differentially regulated at the transcriptional level through the expression of three members of the OsAMT1 family of genes in roots of rice seedlings in response to changes of N status and daily irradiance .
In general , these findings are in agreement with earlier observations in Arabidopsis and tomato . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Differential expression of three members of the AMT1 gene family encoding putative high-affinity NH4+ transporters in roots of Oryza sativa subspecies indica .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Feedback regulation of the ammonium transporter gene family AMT1 by glutamine in rice .
| | Author: Sonoda Y Ikeda A Saiki S Yamaya T Yamaguchi J | | Journal: Plant Cell Physiol .
Citation: V : 44 ( 12 ) P : 1396-402 Year: 2003 Type: ARTICLE | | Literature: oryza Field: title Doc ID: pub14701935 Accession (PMID): 14701935 | | Abstract: The three members of the rice OsAMT1 gene family of ammonium transporters show distinct expression patterns ; constitutive and ammonium-promoted expression in shoots and roots for OsAMT1 ; 1 ; root-specific and ammonium-inducible expression for OsAMT1 ; 2 ; root-specific and nitrogen-repressible expression for OsAMT1 ; 3 [ Sonoda et al ( 2003 ) , Plant Cell Physiol .
44 : 726 ] .
To clarify the feedback mechanisms , and to identify regulatory factors of the OsAMT1 genes , the accumulation of the three mRNAs and its dependence on endogenous nitrogen compounds ( as quantified by capillary electrophoresis ) was studied .
Ammonium application to roots following a period of nitrogen starvation induced accumulation of OsAMT1 ; 1 and OsAMT1 ; 2 mRNA , but a decrease of OsAMT1 ; 3 mRNA levels .
The expression patterns of the three genes showed good correlation ( positive in OsAMT1 ; 1 and OsAMT1 ; 2 , negative in OsAMT1 ; 3 ) with the root it issue contents of glutamine but not of ammonium .
The ammonium effects on OsAMT1 expression were prevented by methionine sulfoximine , an inhibitor of glutamine synthetase .
Moreover , glutamine had the same effect on transcriptional regulation of OsAMT1 genes as ammonium , indicating that glutamine rather than ammonium controls the expression of ammonium transporter genes in rice .
These results imply that rice possesses unique mechanisms of adaptation to variable nitrogen sources in the soil . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Feedback regulation of the ammonium transporter gene family AMT1 by glutamine in rice .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
