Abstract: It is becoming increasingly clear that vitamin C (L-ascorbic acid, AsA) is of crucial importance in such processes as ROS detoxification, photosynthesis and photoprotection, cell division and growth. AsA is also a cofactor for some deoxygenase type enzymes involved in the synthesis of a number of other secondary metabolites and ethylene. A major breakthrough in plant AsA biosynthesis and metabolic engineering has been made recently.