Score: 13.00 |
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| Title: Sucrose transporter1 functions in phloem loading in maize leaves .
| | Author: Slewinski TL Meeley R Braun DM | | Journal: J Exp Bot Citation: V : 60 P : 881-92 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19181865 Accession (PMID): 19181865 | | Abstract: In most plants , sucrose is exported from source leaves to carbon-importing sink it issues to sustain their growth and metabolism .
Apoplastic phloem-loading species require sucrose transporters ( SUTs ) to transport sucrose into the phloem .
In many dicot plants , genetic and biochemical evidence has established that SUT1-type proteins function in phloem loading .
However , the role of SUT1 in phloem loading in monocot plants is not clear since the rice ( Oryza sativa ) and sugarcane ( Saccharum hybrid ) SUT1 orthologues do not appear to function in phloem loading of sucrose .
A SUT1 gene was previously cloned from maize ( Zea mays ) and shown to have expression and biochemical activity consistent with a hypothesized role in phloem loading .
To determine the biological function of SUT1 in maize , a sut1 mutant was isolated and characterized . sut1 mutant plants hyperaccumulate carbohydrates in mature leaves and display leaf chlorosis with premature senescence .
In addition , sut1 mutants have greatly reduced stature , altered biomass partitioning , delayed flowering , and stunted tassel development .
Cold-girdling wild-type leaves to block phloem transport phenocopied the sut1 mutants , supporting a role for maize SUT1 in sucrose export .
Furthermore , application of ( 14 ) C-sucrose to abraded sut1 mutant and wild-type leaves showed that sucrose export was greatly diminished in sut1 mutants compared with wild type .
Collectively , these data demonstrate that SUT1 is crucial for efficient phloem loading of sucrose in maize leaves .
| Matching Sentences:
[ Sen. 6, subscore: 3.00 ]: To determine the biological function of SUT1 in maize , a sut1 mutant was isolated and characterized . sut1 mutant plants hyperaccumulate carbohydrates in mature leaves and display leaf chlorosis with premature senescence .
[ Sen. 4, subscore: 2.00 ]: However , the role of SUT1 in phloem loading in monocot plants is not clear since the rice ( Oryza sativa ) and sugarcane ( Saccharum hybrid ) SUT1 orthologues do not appear to function in phloem loading of sucrose .
[ Sen. 8, subscore: 2.00 ]: Cold-girdling wild-type leaves to block phloem transport phenocopied the sut1 mutants , supporting a role for maize SUT1 in sucrose export .
[ Sen. 9, subscore: 2.00 ]: Furthermore , application of ( 14 ) C-sucrose to abraded sut1 mutant and wild-type leaves showed that sucrose export was greatly diminished in sut1 mutants compared with wild type .
[ Sen. 3, subscore: 1.00 ]: In many dicot plants , genetic and biochemical evidence has established that SUT1-type proteins function in phloem loading .
[ Sen. 5, subscore: 1.00 ]: A SUT1 gene was previously cloned from maize ( Zea mays ) and shown to have expression and biochemical activity consistent with a hypothesized role in phloem loading .
[ Sen. 7, subscore: 1.00 ]: In addition , sut1 mutants have greatly reduced stature , altered biomass partitioning , delayed flowering , and stunted tassel development .
[ Sen. 10, subscore: 1.00 ]: Collectively , these data demonstrate that SUT1 is crucial for efficient phloem loading of sucrose in maize leaves .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 |
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| Title: Three sucrose transporter genes are expressed in the developing grain of hexaploid wheat .
| | Author: Aoki N Whitfeld P Hoeren F Scofield G Newell K Patrick J Offler C Clarke B Rahman S Furbank RT .
| | Journal: Plant Mol . Biol . Citation: V : 50 ( 3 ) P : 453-62 Year: 2002 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12369621 Accession (PMID): 12369621 | | Abstract: A family of three cDNAs , designated TaSUT1A , 1B and 1D , encoding sucrose transporter ( SUT ) proteins was isolated from a hexaploid wheat ( Triticum aestivum ) endosperm library .
The cDNA sequences are 96% identical but are distinguishable from one another by virtue of a size polymorphism in the 3-untranslated region ( UTR ) .
The predicted amino acid sequences are 98% identical and are highly similar to the sucrose transporters from rice , maize and barley .
A gene for TaSUT1 was isolated from genomic libraries of Aegilops tauschii ( the donor of the D genome of wheat ) and the coding sequence found to be identical to that of TaSUT1D cDNA .
There is only one copy of each TaSUT1 gene in hexaploid wheat and it is located on chromosome 4 .
Genomic Southern analysis and PCR analysis across the 3 polymorphic region of hexaploid , tetraploid and progenitor diploid wheat DNAs established that the TaSUT1A gene was present in the putative A-genome progenitor , T monococcum , and that the TaSUT1B gene was present in the putative B-genome progenitor , T searsii .
All three TaSUT1 genes are expressed at high levels in filling grain , showing a good correlation with the developmental time course of growth .
This reinforces the view that in cereals a major role of SUT1 is in the post-phloem sugar transport pathway associated with seed filling .
| Matching Sentences:
[ Sen. 8, subscore: 1.00 ]: This reinforces the view that in cereals a major role of SUT1 is in the post-phloem sugar transport pathway associated with seed filling .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
