Open AccessMeasurement of the Sieve Tube Membrane Potential
Author(s) -
John Paul Wright,
Donald B. Fisher
Publication year - 1981
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.67.4.845
Subject(s) - sieve tube element , depolarization , membrane potential , phloem , sieve (category theory) , membrane , sucrose , chemistry , bark (sound) , biophysics , chromatography , botany , biology , biochemistry , ecology , mathematics , combinatorics
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.