{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/19644"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/19644","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Characterization of sodium transport at the plasma membrane of Spergularia marina","abstract":"Plants vary in their whole plant strategies for managing the sodium (Na$\\sp{+}$) present in their environment, but current models predict that they have a common strategy at the cellular level: exclusion from the cytoplasm. This entails either passive exclusion mediated by low plasma membrane permeability or active exclusion of passively acquired Na$\\sp{+}$ which has moved down its electrochemical gradient into the cell. Whole plant studies using the halophyte Spergularia marina have demonstrated high permeability for Na$\\sp{+}$ into and out of root cells and the research reported here investigates these mechanisms by directly measuring Na$\\sp{+}$ transport using radiolabelled Na$\\sp{+}$ and sealed plasma membrane vesicles from the roots of this species. This is the first report to characterize $\\sp{22}$Na$\\sp{+}$ transport using plant plasma membrane vesicles.","abstract_html":"Plants vary in their whole plant strategies for managing the sodium (Na$\\sp{+}$) present in their environment, but current models predict that they have a common strategy at the cellular level: exclusion from the cytoplasm. This entails either passive exclusion mediated by low plasma membrane permeability or active exclusion of passively acquired Na$\\sp{+}$ which has moved down its electrochemical gradient into the cell. Whole plant studies using the halophyte Spergularia marina have demonstrated high permeability for Na$\\sp{+}$ into and out of root cells and the research reported here investigates these mechanisms by directly measuring Na$\\sp{+}$ transport using radiolabelled Na$\\sp{+}$ and sealed plasma membrane vesicles from the roots of this species. This is the first report to characterize $\\sp{22}$Na$\\sp{+}$ transport using plant plasma membrane vesicles.","abstract_has_math":true,"creators":["Wickens, Linda Karolyn"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Biology, Botany","degree_department":null,"school":null,"contributors":["Cheeseman, John M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:13:57Z","date_published":"2011-05-07T12:13:57Z","updated_at":"2026-07-22T22:25:14Z","subjects":["Biology, Botany","Biology, Cell","Biology, Plant Physiology"],"languages":["eng"],"rights":["Copyright 1991 Wickens, Linda Karolyn"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9211033","(UMI)AAI9211033"],"render_values":[{"text":"AAI9211033","href":null,"code":true},{"text":"(UMI)AAI9211033","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/19644","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Cheeseman, John M."]},{"key":"dc:creator","label":"Author","values":["Wickens, Linda Karolyn"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:13:57Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology, Botany"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology, Botany","Biology, Cell","Biology, Plant Physiology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Wickens, Linda Karolyn"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9211033","(UMI)AAI9211033","http://hdl.handle.net/2142/19644"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Plants vary in their whole plant strategies for managing the sodium (Na$\\sp{+}$) present in their environment, but current models predict that they have a common strategy at the cellular level: exclusion from the cytoplasm. This entails either passive exclusion mediated by low plasma membrane permeability or active exclusion of passively acquired Na$\\sp{+}$ which has moved down its electrochemical gradient into the cell. Whole plant studies using the halophyte Spergularia marina have demonstrated high permeability for Na$\\sp{+}$ into and out of root cells and the research reported here investigates these mechanisms by directly measuring Na$\\sp{+}$ transport using radiolabelled Na$\\sp{+}$ and sealed plasma membrane vesicles from the roots of this species. This is the first report to characterize $\\sp{22}$Na$\\sp{+}$ transport using plant plasma membrane vesicles.","Fractions from discontinuous and linear gradients of sucrose that were enriched in plasma membrane vesicles were identified for use in the $\\sp{22}$Na$\\sp{+}$ transport studies by the orthovanadate-sensitive P-type H$\\sp{+}$-ATPase activity associated with them. Both the scalar and vectoral components of the activity were found to have negligible Na$\\sp{+}$-dependent modifications. Indirect Na$\\sp{+}$-dependent effects were observed, suggesting that Na$\\sp{+}$ could disrupt K$\\sp{+}$-dependent modifications of both components of the ATPase activity. An alternative explanation of the data was that an ATP-dependent, orthovanadate-insensitive, Na$\\sp{+}$-dependent transport mechanism(s) mediated vesicle acidification. Radiolabelled Na$\\sp{+}$ transport studies using similar conditions failed to show the presence of ATP-dependent transport of Na$\\sp{+}$; and in addition, vesicle acidification studies, as well as $\\sp{22}$Na$\\sp{+}$ transport studies, suggested that a Na$\\sp{+}$/H$\\sp{+}$ antiport mechanism was not present in the plasma membrane. Two $\\Delta\\mu\\sb{\\rm Na+}$-driven transport mechanisms were identified using efflux studies. Lineweaver-Burk analysis predicted the presence of a Na$\\sp{+}$ transport mechanism with a K$\\sb{\\rm m}$ of 93 mM Na$\\sp{+}$ and a V$\\sb{\\rm max}$ of 52.6 nmoles Na$\\sp{+}$ $\\cdot$ (mg prot $\\cdot$ min)$\\sp{-1}$. Studies with monensin suggested that there was a Na$\\sp{+}$-dependent alkalinization of the vesicles when the $\\Delta\\mu\\sb{\\rm Na+}$ was high.","Made available in DSpace on 2011-05-07T12:13:57Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9211033.pdf: 5971142 bytes, checksum: 2efa9ed1cab76af1ffe0c37b9b7a2c67 (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:38:27Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:16:02-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Characterization of sodium transport at the plasma membrane of Spergularia marina"]}]}],"canonical_facts":{"dc:contributor":["Cheeseman, John M."],"dc:creator":["Wickens, Linda Karolyn"],"dc:date":["2011-05-07T12:13:57Z","10000-01-01","1991"],"dc:description":["Plants vary in their whole plant strategies for managing the sodium (Na$\\sp{+}$) present in their environment, but current models predict that they have a common strategy at the cellular level: exclusion from the cytoplasm. This entails either passive exclusion mediated by low plasma membrane permeability or active exclusion of passively acquired Na$\\sp{+}$ which has moved down its electrochemical gradient into the cell. Whole plant studies using the halophyte Spergularia marina have demonstrated high permeability for Na$\\sp{+}$ into and out of root cells and the research reported here investigates these mechanisms by directly measuring Na$\\sp{+}$ transport using radiolabelled Na$\\sp{+}$ and sealed plasma membrane vesicles from the roots of this species. This is the first report to characterize $\\sp{22}$Na$\\sp{+}$ transport using plant plasma membrane vesicles.","Fractions from discontinuous and linear gradients of sucrose that were enriched in plasma membrane vesicles were identified for use in the $\\sp{22}$Na$\\sp{+}$ transport studies by the orthovanadate-sensitive P-type H$\\sp{+}$-ATPase activity associated with them. Both the scalar and vectoral components of the activity were found to have negligible Na$\\sp{+}$-dependent modifications. Indirect Na$\\sp{+}$-dependent effects were observed, suggesting that Na$\\sp{+}$ could disrupt K$\\sp{+}$-dependent modifications of both components of the ATPase activity. An alternative explanation of the data was that an ATP-dependent, orthovanadate-insensitive, Na$\\sp{+}$-dependent transport mechanism(s) mediated vesicle acidification. Radiolabelled Na$\\sp{+}$ transport studies using similar conditions failed to show the presence of ATP-dependent transport of Na$\\sp{+}$; and in addition, vesicle acidification studies, as well as $\\sp{22}$Na$\\sp{+}$ transport studies, suggested that a Na$\\sp{+}$/H$\\sp{+}$ antiport mechanism was not present in the plasma membrane. Two $\\Delta\\mu\\sb{\\rm Na+}$-driven transport mechanisms were identified using efflux studies. Lineweaver-Burk analysis predicted the presence of a Na$\\sp{+}$ transport mechanism with a K$\\sb{\\rm m}$ of 93 mM Na$\\sp{+}$ and a V$\\sb{\\rm max}$ of 52.6 nmoles Na$\\sp{+}$ $\\cdot$ (mg prot $\\cdot$ min)$\\sp{-1}$. Studies with monensin suggested that there was a Na$\\sp{+}$-dependent alkalinization of the vesicles when the $\\Delta\\mu\\sb{\\rm Na+}$ was high.","Made available in DSpace on 2011-05-07T12:13:57Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9211033.pdf: 5971142 bytes, checksum: 2efa9ed1cab76af1ffe0c37b9b7a2c67 (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:38:27Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:16:02-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9211033","(UMI)AAI9211033","http://hdl.handle.net/2142/19644"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Wickens, Linda Karolyn"],"dc:subject":["Biology, Botany","Biology, Cell","Biology, Plant Physiology"],"dc:title":["Characterization of sodium transport at the plasma membrane of Spergularia marina"],"dc:type":["text"],"thesis:degree_discipline":["Biology, Botany"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:14Z"}