Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1994-3-16
pubmed:abstractText
Sucrose is the principal transport form of assimilates in most plants. In many species, translocation of assimilates from the mesophyll into the phloem for long distance transport is assumed to be carrier mediated. A putative sucrose proton cotransporter cDNA has been isolated from potato and shown to be expressed mainly in the phloem of mature exporting leaves. To study the in vivo role and function of the protein, potato plants were transformed with an antisense construct of the sucrose transporter cDNA under control of the CaMV 35S promoter. Upon maturation of the leaves, five transformants that expressed reduced levels of sucrose transporter mRNA developed local bleaching and curling of leaves. These leaves contained > 20-fold higher concentrations of soluble carbohydrates and showed a 5-fold increase in starch content as compared with wild type plants, as expected from a block in export. Transgenic plants with a reduced amount of sucrose carrier mRNA show a dramatic reduction in root development and tuber yield. Maximal photosynthetic activity was reduced at least in the strongly affected transformants. The effects observed in the antisense plants strongly support an apoplastic model for phloem loading, in which the sucrose transporter located at the phloem plasma membrane represents the primary route for sugar uptake into the long distance distribution network.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-11607409, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-1303802, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-1464305, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16453867, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16652961, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16653098, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16658661, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16662694, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16665257, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16666044, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16667661, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-16668000, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-1703626, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-1844880, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-2209536, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-2532612, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-6095209, http://linkedlifedata.com/resource/pubmed/commentcorrection/8306952-8327465
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0261-4189
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-7
pubmed:dateRevised
2010-9-10
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Evidence for an essential role of the sucrose transporter in phloem loading and assimilate partitioning.
pubmed:affiliation
Institut für Genbiologische Forschung, Berlin, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't