Secondary metabolites vacuolar transport

Secondary metabolites in plant cell culture are typically stored within the vacuolar compartments of the cells. Small amounts of metabolites are usually excreted into the medium or may appear in the medium due to cell lysis. In some cases, active transport of metabolites adjusts intracellular and extracellular levels in response to cellular conditions. Poor yields of secondary substances released into the medium may be caused by several factors. In those cases where low yield is due to cellularly mediated regulation of the ratio between intracellular and extracellular product concentrations, processes which reduce net medium concentrations such as enzymatic or non-enzymatic degradation, or volatility, should increase net production by depleting the level of the secondary substances in the culture medium. By using the so-called in situ extraction method, the accumulation of a secondary substance inside the cell, in the culture medium, and in the extraction phase should approach an equilibrium, which... 

Martinoia, E. et al. (2001) Vacuolar transport of secondary metabolites and xenobiotics. In Vacuolar Compartments (Robinson, D. and Rogers, J., eds), pp. 221-253, Sheffield Academic Press, Sheffield... 

---