Pattern of enzymes involved in cyanogenesis and HCN metabolism in cell cultures of Phaseolus lunatus L. varieties

Callus and cell suspension cultures were established from root and shoot tips of aseptically-grown seedlings of highly cyanogenic Phaseolus lunatus L. varieties. The content of cyanogenic glucosides in the explanted seedling sections decreased during storage, the derived callus cells were free of cyanogenic glycosides. In spite of the non-existence of cyanogenic glucosides, the cyanogen degrading linamarase, the cyanide detoxifying enzyme ß-cyanoalanine synthase and also hydroxynitrile lyase were still present in suspension cultures. The linamarase activity equalled the total ß-glucosidase activity, of which up to 80% was found in the culture medium. In contrast the ß-cyanoalanine synthase and the hydroxy nitrile lyase were entirely localized in the cell biomass.