SIMULTANEOUS MEASUREMENT OF FOLIAR GLUTATHIONE, GAMMA-GLUTAMYLCYSTEINE, AND AMINO-ACIDS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY - COMPARISON WITH 2 OTHER ASSAY-METHODS FOR GLUTATHIONE

The recent production of transformed plants with enhanced capacity for glutathione synthesis has highlighted the interactions between foliar glutathione and turnover of free amino acid pools. The development of a convenient method for simultaneous measurement of glutathione, gamm a-glutamylcysteine, and 16 amino acids is reported. This method utiliz es derivatization of compounds with o-phthalaldehyde in the presence o f a-mercaptoethanol followed by separation using reversed-phase high-p erformance liquid chromatography, fluted compounds are detected fluori metrically. The method was tested using untransformed poplars and popl ars in which foliar thiol contents have been enhanced by overexpressio n of gamma-glutamylcysteine synthetase. Foliar contents of glutathione determined by this method were comparable to those measured in common extracts by two other techniques. (C) 1998 Academic Press.