Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-6-29
pubmed:abstractText
Sugar release from the pedicel tissue of maize (Zea mays L.) kernels was studied by removing the distal portion of the kernel and the lower endosperm, followed by replacement of the endosperm with an agar solute trap. Sugars were unloaded into the apoplast of the pedicel and accumulated in the agar trap while the ear remained attached to the maize plant. The kinetics of (14)C-assimilate movement into treated versus intact kernels were comparable. The rate of unloading declined with time, but sugar efflux from the pedicel continued for at least 6 hours and in most experiments the unloading rates approximated those necessary to support normal kernel growth rates. The unloading process was challenged with a variety of buffers, inhibitors, and solutes in order to characterize sugar unloading from this tissue.Unloading was not affected by apoplastic pH or a variety of metabolic inhibitors. Although p-chloromercuribenzene sulfonic acid (PCMBS), a nonpenetrating sulfhydryl group reagent, did not affect sugar unloading, it effectively inhibited extracellular acid invertase. When the pedicel cups were pretreated with PCMBS, at least 60% of sugars unloaded from the pedicel could be identified as sucrose. Unloading was inhibited up to 70% by 10 millimolar CaCl(2). Unloading was stimulated by 15 millimolar ethyleneglycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid which partially reversed the inhibitory effects of Ca(2+). Based on these results, we suggest that passive efflux of sucrose occurs from the maize pedicel symplast followed by extracellular hydrolysis to hexoses.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16656904, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16657924, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16657925, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16658491, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16658661, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16659588, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16659931, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16660089, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16660612, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16661298, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16661619, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16661775, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16662827, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16662976, http://linkedlifedata.com/resource/pubmed/commentcorrection/16664091-16663007
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Mar
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
77
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
524-31
pubmed:dateRevised
2010-9-14
pubmed:year
1985
pubmed:articleTitle
Sugar Efflux from Maize (Zea mays L.) Pedicel Tissue.
pubmed:affiliation
Department of Agronomy, The Pennsylvania State University, University Park, Pennsylvania 16802.
pubmed:publicationType
Journal Article