Radial electrogenic activity in the stem of Vigna sesquipedalis : involvement of spatially separate pumps
1978; Wiley; Volume: 1; Issue: 4 Linguagem: Inglês
10.1111/j.1365-3040.1978.tb02040.x
ISSN1365-3040
AutoresHISASHl OKAMOTO, Kazuo Ichino, Kiyoshi Katou,
Tópico(s)Plant Genetic and Mutation Studies
ResumoAbstract. 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.
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