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Large plasma-membrane depolarization precedes rapid blue-light-induced growth inhibition in cucumberBlue-light (BL)-induced suppression of elongation of etiolated Cucumis sativus L. hypocotyls began after a 30-s lag time, which was halved by increasing the fluence rate from 10 to 100 micromoles m-2 s-1. Prior to the growth suppression, the plasma-membrane of the irradiated cells depolarized by as much as 100 mV, then returned within 2-3 min to near its initial value. The potential difference measured with surface electrodes changed with an identical time course but opposite polarity. The lag time for the change in surface potential showed an inverse dependence on fluence rate, similar to the lag for the growth inhibition. Green light and red light caused neither the electrical response nor the rapid inhibition of growth. The depolarization by BL did not propagate to nonirradiated regions and exhibited a refractory period of about 10 min following a BL pulse. Fluence-response relationships for the electrical and growth responses provide correlational evidence that the plasma-membrane depolarization reflects an event in the transduction chain of this light-growth response.
Document ID
20040090328
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Spalding, E. P. (University Park 16802 United States)
Cosgrove, D. J.
Date Acquired
August 21, 2013
Publication Date
January 1, 1989
Publication Information
Publication: Planta
Volume: 178
ISSN: 0032-0935
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: DMB-8351030
Distribution Limits
Public
Copyright
Other
Keywords
NASA Program Space Biology
NASA Discipline Number 29-20
Non-NASA Center
NASA Discipline Plant Biology