ISSN:
1432-2048
Keywords:
Glucose cotransport
;
H+-glucose cotransport
;
Lemna
;
Membrane potential
;
pH changes, external
;
Transport, glucose
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Extracellular pH was measured with a microelectrode positioned over the lower surface of singleLemna gibba plants. Upon addition of glucose, a transient extracellular alkalinization occurred. Saturated extracellular pH changes were observed with 5 mM glucose. Simultaneously, the membrane potential difference of −250 mV in the dark measured with intracellular glass micropipettes, trnasiently decreased by 105 mV. Uptake of [14C]glucose and extracellular alkalinization was enhanced by light whereas glucose-induced membrane-potential changes were reduced in the light and became even smaller with increasing the preillumination time. Glucose uptake was optimal at pH 6. The results are taken as further evidence in favor of H+-glucose cotransport inLemna.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00571164
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