The Relation of Glucose Absorption to Respiration in Potato Slices

Multiphasic Absorption of Glucose and 3-O-Methyl Glucose by Aged Potato Slices

“…The core section was pierced with a 10 mm diameter stainless steel tube, and the 10 mm tissue core subsequently was sliced to yield 1 mm thick discs. The discs were aged for 24 hr with gentle rotary shaking (15). The washing solution (0.2 mm CaSO4) was changed eight times over the first 12 hr.…”

“…Initial studies on "C-glucose uptake were done using the method described by Laties (15). "C loss from solution was measured by removing 50-,ul samples at designated time intervals, drying the samples on small circles of glass filter paper, placing the latter into a toluene-fluor solution (PPO-POPOP), and counting with a Nuclear Chicago 720 liquid scintillation system.…”

“…Significant questions which persist regarding the process of glucose absorption in higher plant tissues are best revealed by a comparison of the observations of Grant and Beevers (10) on glucose absorption by carrot slices and of Laties (15) on glucose uptake by potato discs. Grant and Beevers describe an absorption process which is putatively a smooth hyperbolic function of concentration with an apparent Km of approximately 10 mm.…”

“…The recognition of multiplicity in inorganic ion uptake suggested to us that the observations of Grant and Beevers (10) and of Laties (15) Whether one observes plasma membrane-limited or tonoplast-limited absorption rates depends on the experimental protocol in relation to the compartment exchange times for cytoplasm and vacuole respectively (4). For certain ions at least, plasma membrane and tonoplast influx have been separately estimated (5).…”

The Regulation of Sugar Uptake and Accumulation in Bean Pod Tissue

“…There was no significant difference betweeni the effect of these inhibitors. For potato slices, exposed to similar concentrations of glucose and these inlhibitors, total absorption (cpm removed from ambient solution) was inhibited 45 % by KCN and 32 % by dinitrophenol (14). Seven experiments were conducted in which tissue sections were incubated in solutions of 0.03 M with respect to both glucose and fructose, with only one of the sugars labeled.…”