title: Ca(2+) transport in mitochondrial and microsomal fractions from higher plants.
abstract: Mitochondria from etiolated corn possess a much greater Ca(2+) uptake capacity per mg protein than microsomes from the same source. Differences in energy requirements, sensitivity to specific inhibitors, and sedimentation properties enabled us to study both Ca(2+) uptake mechanisms without mutual contamination. The microsomal Ca(2+) uptake does not vary much among different plants as compared to the mitochondrial Ca(2+) uptake; this is also true for different organs of the same plant. Mitochondrial Ca(2+) uptake is more dependent on the age of the seedlings than microsomal uptake, because of changes in active Ca(2+) uptake activity rather than of changes in efflux. Intactness and the oxidative and phosphorylative properties of the mitochondria remained unchanged during this time period. Na(+) and Mg(2+) do not induce Ca(2+) release from mitochondria.
authors.affiliation: Institut für Biologie III der Universität Freiburg, Schänzlestraße 1, D-7800, Freiburg, Federal Republic of Germany.
authors.forename: P
authors.initials: P
authors.lastname: Dieter
authors.forename: D
authors.initials: D
authors.lastname: Marmé