Active and passive calcium transport systems in plant cells: Progress report, January 1986-September 1986

Technical Report · Wed Oct 01 00:00:00 EDT 1986

OSTI ID:5363588

Sze, H

Two types of ATP-dependent Ca transport systems have been identified in isolated membrane vesicles from oat roots. The properties of the Ca pumps have been partially characterized and the membrane identity has been established. One pump predominantly on the ER is a Ca-pumping ATPase, and the other is a Ca/H antiport system dependent on the electrochemical gradient from the tonoplast-type H-ATPase. Though the two systems differe in several respects, they may both be important for regulating cytoplasmic (Ca) by removing Ca from the cytoplasm. We have also examined how a fungal toxin (Helminthosporium maydis T) might alter membrane functions. The HmT toxin decreased active Ca transport into mitochondria from susceptible corn by increasing membrane permeability to Ca and H/sup +/. We found that the toxin alone increased conductance of planar bilayer membranes to cations. The dependence of Ca fluxes on the pH gradient and membrane potential or both, stresses the need to understand the mode of toxin action on membrane functions in general. 5 figs., 3 tabs.

• Research Organization: Maryland Univ., College Park (USA). Dept. of Botany
• DOE Contract Number: FG05-86ER13461
• OSTI ID: 5363588
• Report Number(s): DOE/ER/13461-1; ON: DE88006532
• Resource Relation: Other Information: Paper copy only, copy does not permit microfiche production
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CALCIUM
MEMBRANE TRANSPORT
PORINS
BIOCHEMICAL REACTION KINETICS
FRACTIONATION
ATP-ASE
CARROTS
ENZYME INHIBITORS
MICROSOMES
NICOTIANA
OATS
PH VALUE
PROGRESS REPORT
ACID ANHYDRASES
ALKALINE EARTH METALS
CELL CONSTITUENTS
CEREALS
DOCUMENT TYPES
ELEMENTS
ENZYMES
FOOD
GRASS
HYDROLASES
KINETICS
MEMBRANE PROTEINS
METALS
ORGANIC COMPOUNDS
ORGANOIDS
PHOSPHOHYDROLASES
PLANTS
PROTEINS
REACTION KINETICS
SEPARATION PROCESSES
VEGETABLES
550200* - Biochemistry