A new plant gene in the pathway to vitamin C

Authors: Giovannoni, James

Submitted to: Proceedings of the National Academy of Sciences (PNAS)
Publication Type: Popular Publication
Publication Acceptance Date: 7/12/2007
Publication Date: 8/5/2007
Citation: Giovannoni, J.J. 2007. A new plant gene in the pathway to vitamin C. Proceedings of the National Academy of Sciences. 104:9109-9110.

Interpretive Summary: L-Ascorbic acid (vitamin C or L-ascorbate) is a metabolite with strong antioxidant activity and a cofactor for enzymes catalyzing numerous biochemical reactions including those neutralizing the effects of reactive oxygen species (ROS). It is also a necessary nutrient for a limited number of animals, including humans, that are incapable of its synthesis and who must secure vitamin C via dietary uptake. Plants produce large amounts of L-ascorbic acid to facilitate resistance to oxidative stresses associated with myriad biotic and abiotic challenges and inherent to photosynthesis. Plants are also the primary source of vitamin C intake with respect to human diets. Consequently, the study of plant ascorbate synthesis is highly relevant to both plant biology and human nutrition with eventual engineering of plant ascorbate metabolism a logical and important target for crop quality improvement.

Technical Abstract: Worldwide vitamin C deficiency is considered a problem of limited scope primarily in developing nations of Africa and South Asia where supply of fresh fruits and vegetables can be unreliable and availability of vitamin supplements limited. While the more severe effects of vitamin C deficiency (connective tissue defects, poor wound healing, and tooth loss) are rare in developed nations, significant proportions of said populations have intake levels below recommended levels. Strategies to manipulate crop plants for elevated vitamin C accumulation will thus be important in both developing and developed nations and the completion of the gene repertoire for plant L-Galactose pathway to ascorbate should facilitate further studies toward understanding regulatory control of ascorbate accumulation and opportunities for increased vitamin C content of food crops.