ABSTRACT
Isolated protoplasts offer much promise as a model system for studies on membrane transport in plants. Studies of membrane transport using protoplasts require the rapid isolation of large quantities of pure, viable protoplasts. The rate of inorganic ion transport into plant cells responds in a characteristic fashion to increasing concentrations of the ion. The transport of charged and uncharged ions and metabolites is directly or indirectly influenced by the membrane potential. Major transport functions have been suggested for the vacuole, but many remain only hypothetical as it is very difficult to study transport through the tonoplast membrane of intact cells. The isolation and biochemical characterization of the plasma membrane is dependent on the separation of the membrane from other cellular components. The ability to obtain large quantities of viable protoplasts from a variety of plant tissues and species has proven to be important for research on membrane transport in plants.
