Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2010-6-29
pubmed:abstractText
The concentration of osmotically active solutes in the cell wall free space of young stem tissues was studied using a variety of extraction methods. When the intercellular air spaces of etiolated pea (Pisum sativum L.) internodes were perfused with distilled H(2)O, the resulting solution contained a solute concentration of about 70 milliosmoles per kilogram. A second procedure involving vacuum infiltration of segments followed by centrifugation to collect the free space solution gave similar results. Apical stem segments yielded free space extracts about twice as concentrated as those from basal portions of the stem. After correcting for dilution of the free space solution by the infiltrated water, the osmotic pressure of the undiluted free space in pea stem tissue was estimated to be 2.9 bars for apical segments, 1.8 bars for basal regions. These values may be somewhat overestimated due to solute efflux from intracellular pools during the extraction procedure. Similar results were obtained for stem regions of etiolated soybean (Glycine max [L.] Merr.) and cucumber (Cucumis sativus L.) seedlings.From measurements of the electrical conductivity and refractive index of free space extracts before and after ashing, it appears that 25% of the solutes are inorganic electrolytes and 75% are organic nonelectrolytes with an average size similar to that of glucose.A significant osmotic pressure in the wall space offers an explanation for the frequent observation that nontranspiring plants have negative water potentials. Calculations of hydraulic resistance from water potential data must take into account solutes in the free space, else ;apparent,' but unreal, changes in resistance may be calculated.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16655968, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16656467, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16656476, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16657623, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16660623, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16661430, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16661595, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16661927, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16661952, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-16663002, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-17832103, http://linkedlifedata.com/resource/pubmed/commentcorrection/16663001-957691
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jun
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
326-31
pubmed:dateRevised
2010-9-15
pubmed:year
1983
pubmed:articleTitle
Solutes in the free space of growing stem tissues.
pubmed:affiliation
Department of Botany, University of Washington, Seattle, Washington 98195.
pubmed:publicationType
Journal Article