Differential effects of plasma membrane electric excitation on H+ fluxes and photosynthesis in characean cells.
Bioelectrochemistry
; 69(2): 209-15, 2006 Oct.
Article
in En
| MEDLINE
| ID: mdl-16627011
ABSTRACT
Cells of characean algae exposed to illumination arrange plasma-membrane H(+) fluxes and photosynthesis in coordinated spatial patterns (bands). This study reveals that H(+) transport and photosynthesis patterns in these excitable cells are affected not only by light conditions but also by electric excitation of the plasma membrane. It is shown that generation of action potential (AP) temporally eliminates alkaline bands, suppresses O(2) evolution, and differentially affects primary reactions of photosystem II (PSII) in different cell regions. The quantum yield of PSII electron transport decreased after AP in the alkaline but not in acidic cell regions. The effects of electric excitation on fluorescence and the PSII electron flow were most pronounced at light-limiting conditions. Evidence was obtained that the shift in chlorophyll fluorescence after AP is due to the increase in DeltapH at thylakoid membranes. It is concluded that the AP-triggered pathways affecting ion transport and photosynthetic energy conversion are linked but not identical.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Photosynthesis
/
Protons
/
Action Potentials
/
Cell Membrane
/
Characeae
/
Electric Stimulation
/
Membrane Potentials
Language:
En
Journal:
Bioelectrochemistry
Journal subject:
BIOQUIMICA
Year:
2006
Document type:
Article
Affiliation country:
RUSSIA
Publication country:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS