Transport properties of tomato fruit tonoplast membrane vesicles

Conference · Mon Mar 31 23:00:00 EST 1986 · Plant Physiol., Suppl.; (United States)

OSTI ID:5122026

Oleski, N; Joyce, D; Osteryoung, K; Bennett, A B

To study the role of the tonoplast in tomato fruit development, methods were developed to isolate sealed tonoplast membrane vesicles. Low density (approx. 1.23 g/cc) membrane vesicles they found to possess a NO/sub 3//sup -/-sensitive H/sup +/-translocating ATPase. The properties of this H/sup +/-ATPase are similar to those described for other tonoplast H/sup +/-ATPases. ATP-dependent Ca/sup + +/ transport into the vesicles proceeded by two mechanisms, one operative at low Ca/sup + +/ concentrations (1 ..mu..M) and inhibited by vanadate, and the other operative at high Ca/sup + +/ concentrations (10 ..mu..M) and inhibited by NO/sub 3//sup -/. Their present results indicate that the high affinity (vanadate-sensitive) Ca/sup + +/ transporter resides in E.R. membrane that contaminates the tonoplast preparation. Citrate uptake in tonoplast vesicles is stimulated by ATP and inhibited by NO/sub 3//sup -/ suggesting that citrate uptake is driven indirectly by the H/sup +/-ATPase. The substrate for sugar uptake is UDP-glucose resulting in the appearance of sucrose inside the tonoplast vesicle. No evidence for ATP stimulation of glucose, fructose, or sucrose uptake was observed.

• Research Organization: Univ. of California, Davis
• OSTI ID: 5122026
• Journal Information: Plant Physiol., Suppl.; (United States), Journal Name: Plant Physiol., Suppl.; (United States) Vol. 80:4; ISSN PPYSA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ALKALINE EARTH METALS
ATP-ASE
BIOLOGICAL EFFECTS
CALCIUM
CARBOXYLIC ACID SALTS
CELL CONSTITUENTS
CELL MEMBRANES
CITRATES
ELEMENTS
ENZYMES
FOOD
FRUITS
GROWTH
HYDROLASES
MEMBRANE TRANSPORT
MEMBRANES
METALS
NITRATES
NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHOHYDROLASES
PLANT CELLS
PLANT GROWTH
TOMATOES
UPTAKE