Classification of Terpenoids according to the Methylerythritolphosphate or the Mevalonate Pathway with Natural12C/13C Isotope Ratios: Dynamic Allocation of Resources in Induced Plants

Plants utilize two different pathways for the biosynthesis of isopentenyl diphosphate, the universal building block of all terpenes (see scheme). Application of compound-specific isotope-ratio mass spectrometry (GC-C-IRMS) to volatile terpenoids allows distinction between the pathways on the basis of natural 12C/13C ratios.