Ascorbate as a biosynthetic precursor in plants.
OBJECTIVE
l-Ascorbate (vitamin C) has well-documented roles in many aspects of redox control and anti-oxidant activity in plant cells. This Botanical Briefing highlights recent developments in another aspect of l-ascorbate metabolism: its function as a precursor for specific processes in the biosynthesis of organic acids.


METHODS
The Briefing provides a summary of recent advances in our understanding of l-ascorbate metabolism, covering biosynthesis, translocation and functional aspects. The role of l-ascorbate as a biosynthetic precursor in the formation of oxalic acid, l-threonic acid and l-tartaric acid is described, and progress in elaborating the mechanisms of the formation of these acids is reviewed. The potential conflict between the two roles of l-ascorbate in plant cells, functional and biosynthetic, is highlighted.


CONCLUSIONS
Recent advances in the understanding of l-ascorbate catabolism and the formation of oxalic and l-tartaric acids provide compelling evidence for a major role of l-ascorbate in plant metabolism. Combined experimental approaches, using classic biochemical and emerging 'omics' technologies, have provided recent insight to previously under-investigated areas.
Debolt
Seth
S
School of Agriculture, Food and Wine, University of Adelaide, Waite Campus, PMB1, Glen Osmond, SA 5064, Australia.
Melino
Vanessa
V
Ford
Christopher M
CM
D001205:Ascorbic Acid / Q000378:metabolism*; D005638:Fruit / Q000378:metabolism; D019815:Oxalic Acid / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D013644:Tartrates / Q000378:metabolism*; D027843:Vitis / Q000378:metabolism
D013644:Tartrates; D019815:Oxalic Acid; D001205:Ascorbic Acid; C029768:tartaric acid