Stable Isotope Labeling and Quantification of Photosynthetic Metabolites.

Stable isotope labeling with 13 CO 2 coupled with mass spectrometry allows monitoring the incorporation of 13 C into photosynthetic intermediates and is a powerful technique for the investigation of the metabolic dynamics of photosynthesis. We describe here a protocol for 13 CO 2 labeling of large leaved plants and of Arabidopsis thaliana rosette, and a method for quantitative mass spectrometry analyses to uncover the labeling pattern of Calvin-Benson cycle sucrose, and starch synthesis as well as carbon-concentrating mechanism metabolites.