Pyrophosphate-dependent H sup + /Ca sup 2+ -antiport activity in tonoplast vesicles from maize roots

Conference · Tue May 01 00:00:00 EDT 1990 · Plant Physiology, Supplement; (USA)

OSTI ID:5627802

Chanson, A; Pilet, P -E ^[1]

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1. Institute of Plant Biology and Physiology of the University, Lausanne (Switzerland)

Pyrophosphate (PPi)-dependent calcium uptake by tonoplast enriched membranes vesicles from maize (Zea mays L. cv LG 11) primary roots was studied. The Ca{sup 2+} uptake was measured using {sup 45}Ca{sup 2+}, and found to be linear for 10 min when oxalate (10 mM) was present. The Ca{sup 2+} transport was completely inhibited by some proton ionophores (FCCP and monensin), arguing for a Ca{sup 2+}/H{sup +} antiport. No interferences due to the ATP-dependent Ca{sup 2+} pumps from the plasmalemma and the ER were obtained. Membranes were further fractionated using linear sucrose gradients (10-45%) and identified with marker enzymes. The Ca{sup 2+} uptake distribution was similar to those of the tonoplast PPi-dependent proton pumping, pyrophosphatase and ATPase activities. The Ca{sup 2+}/H{sup +} antiport is consequently located on the tonoplast. Data will be presented on the characterization of the Ca{sup 2+}/H{sup +} antiport.

• OSTI ID: 5627802
• Report Number(s): CONF-9007196-; CODEN: PPYSA
• Journal Information: Plant Physiology, Supplement; (USA), Vol. 93:1; Conference: Annual meeting of the American Society of Plant Physiologists, Indianapolis, IN (USA), 29 Jul - 2 Aug 1990; ISSN 0079-2241
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CALCIUM
UPTAKE
ATP-ASE
CALCIUM 45
CALCIUM COMPOUNDS
MAIZE
MEMBRANE TRANSPORT
ROOTS
TRACER TECHNIQUES
ACID ANHYDRASES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALCIUM ISOTOPES
CEREALS
DAYS LIVING RADIOISOTOPES
ELEMENTS
ENZYMES
EVEN-ODD NUCLEI
GRAMINEAE
HYDROLASES
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
LILIOPSIDA
MAGNOLIOPHYTA
METALS
NUCLEI
PHOSPHOHYDROLASES
PLANTS
RADIOISOTOPES
550501* - Metabolism- Tracer Techniques