Premium
Radial electrogenic activity in the stem of Vigna sesquipedalis : involvement of spatially separate pumps
Author(s) -
OKAMOTO HISASHl,
ICHINO KAZUO,
KATOU KIYOSHI
Publication year - 1978
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/j.1365-3040.1978.tb02040.x
Subject(s) - vigna , xylem , parenchyma , symplast , chemistry , potential difference , botany , biophysics , horticulture , biology , cell wall , electrode , apoplast
. The surface electric potential of Vigna sesquipedalis stem, relative to that of the root medium, was most negative in the elongating zone where the difference in pH between parenchyma (P) and xylem sap (X) was at a maximum. The surface electrical potential was found to be determined by the distribution of radial potential difference ( V sx comprised two components; V sx = V px − V ps .There were two electromotive forces, generating V ps at the surface of the parenchyma symplast and V px between P and X; both were partially dependent on respiration. The depolarization of V px upon removal of O 2 was maximal in the elongating zone, suggesting that the activity of an H + ‐pump extruding protons from the parenchyma into the xylem in exchange for K + was greatest in this zone.