ISSN:
1432-2048
Keywords:
Amino acid uptake
;
Lycopersicon
;
Potassium co-transport
;
Proton co-transport
;
Sugar uptake
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Internode disks of tomato (Lycopersicon esculentum cv. Moneymaker) were shaken in glutamine and sucrose solutions. At low external pH (〈±5.5), the uptake of these substances was accompanied with K+ efflux, at high pH (〉±5.5) with K+ influx. Low concentrations of external K+ (2 mmol l-1) stimulated the uptake of glutamine, which was strongly inhibited by the supply of high K+ concentrations (20 mmol l-1). The effect of K+ was particularly pronounced at high pH-values. Addition of CCCP in light reduced the uptake of glutamine to the same level as in the dark, and stopped the K+ fluxes which coincided with the uptake. A model is presented wherein the movements of K+ across the membrane are related to co-transport, depending on the membrane potential and the Nernst potential of K+.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00379930
Permalink