A rapid method for measuring organelle-specific substrate transport in homogenates from plant tissues

A rapid method is described for measuring organelle-specific metabolite transport systems in crude homogenates from plants. The tissues were homogenized in liquid nitrogen, extracted with buffer and reconstituted into artificial membranes. The method allowed demonstration of the known different substrate specificities of chloroplast triose phosphate/phosphate translocators from C₃- and C₄-plants, of the triose phosphate/phosphate translocator from non-green tissue, and of the dicarboxylate translocator. It thus by-passes the necessity to isolate intact plant organelles and, in addition, only a low amount of tissue material is required for transport measurements.Abbreviations Chl chlorophyll - TPT triose phosphate/phosphate translocatorDedicated to Professor F.-C. Czygan on the occasion of his 60th birthdayThis research was supported by the Bundesministerium für Forschung und Technologie. A.W. is a recipient of a Ph.D. fellowship from the Deutsche Forschungsgemeinschaft.