Abstract
A procedure is described for the measurement of the sieve tube membrane potential in the phloem of bark strips from Salix exigua Nutt. Measurements were made by inserting a measuring microelectrode into sap exuding from severed stylets of the willow aphid, Tuberolachnus salignus. Data taken from 20 bark strips gave an average potential of −155 ± 9 millivolts. Evidence is presented for an electrogenic component of the sieve tube membrane potential. The occurrence of a saturable sucrose-induced membrane depolarization is consistent with the concept of sugar accumulation by a sucrose/H+ co-transport mechanism.
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Selected References
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- Giaquinta R. T. Phloem loading of sucrose: involvement of membrane ATPase and proton transport. Plant Physiol. 1979 Apr;63(4):744–748. doi: 10.1104/pp.63.4.744. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Winne D. Unstirred layer, source of biased Michaelis constant in membrane transport. Biochim Biophys Acta. 1973 Feb 27;298(1):27–31. doi: 10.1016/0005-2736(73)90005-9. [DOI] [PubMed] [Google Scholar]