Blue light inactivates plasma membrane H(+)-ATPase in pulvinar motor cells of Phaseolus vulgaris L.
Plant Cell Physiol
; 43(8): 860-8, 2002 Aug.
Article
in En
| MEDLINE
| ID: mdl-12198188
ABSTRACT
Unilateral blue light irradiation induces bending of pulvini of Phaseolus vulgaris towards the source of light. The pulvinar bending is caused by a decrease in turgor pressure of motor cells that are irradiated with blue light. Decrease in the turgor pressure is caused by the net efflux of K(+) and counter anions, accompanying membrane depolarization. In the present study the effect of blue light on the activity of plasma membrane H(+)-ATPase was studied in relation to the membrane depolarization. The activity of the plasma membrane H(+)-ATPase was measured using protoplast suspensions prepared from laminar pulvini from primary leaves. A pulse of blue light under continuous red light irradiation induced both a transient increase in the external pH and transient inhibition of the vanadate-sensitive ATPase. Continuous blue light irradiation under continuous red light irradiation induced both a sustained increase in the external pH and sustained inhibition of the vanadate-sensitive ATPase. These results show that blue light inhibits the activity of the plasma membrane H(+)-ATPase. Inactivation of the plasma membrane H(+)-ATPase supports the membrane depolarization induced by the blue light irradiation.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cell Movement
/
Proton-Translocating ATPases
/
Pulvinus
/
Phaseolus
Language:
En
Journal:
Plant Cell Physiol
Journal subject:
BOTANICA
Year:
2002
Document type:
Article