ISSN:
1573-5087
Keywords:
dormancy
;
aleurone
;
inward rectifying K+ channels
;
potassium
;
patch-clamp
;
barley
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Isogenic dormant and non-dormant barley grains provide a useful system to study the molecular mechanisms of grain dormancy and the role of plant hormones in this process. As ion fluxes are associated with dormancy-related plant hormone responses, we compared the properties of the inward rectifying potassium conductance in aleurone protoplasts isolated from dormant and non-dormant Triumph grains and in germinating Himalaya grains. Maximal conductance, voltage dependency of steady-state activation, activation and deactivation kinetics were studied in the whole-cell patch-clamp configuration. Activation and deactivation time courses were single exponential. No differences in the above described properties were found between the protoplasts isolated from non-dormant Triumph and Himalaya grains. However, the maximal conductance (corrected for cell size) in protoplasts from dormant Triumph grains was much smaller (65%), and activation time constants were much larger as compared to protoplasts from non-dormant grains. No differences were found in the deactivation kinetics in the three different types of protoplasts. The half-maximal activation potential was slightly more negative in protoplasts from dormant grains than from non-dormant grains.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00028495
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