More vitamin C

Vitamin C (L-Ascorbic acid) is an essential dietary nutrient found in fruits and vegetables: it has crucial antioxidant roles in the immune system and in the synthesis of collagen, carnitine, and neurotransmitters, but little has been known about vitamin C biosynthesis in plants. In the January 13 Nature Biotechnology, Fernanda Agius and colleagues at the Universidad de Málaga, Málaga, Spain, show that GalUR, encoding a D-galacturonic acid reductase, controls vitamin C synthesis and can be use to increase vitamin C production in plants (Nature Biotechnology, doi:10.1038/nbt777, January 13, 2003).

Using strawberries Agius et al. observed that the biosynthesis of L-ascorbic acid occurs through D-galacturonic acid — a principal component of cell wall pectins. In addition, they identified GalUR, a gene from strawberry that encodes an NADPH-dependent D-galacturonate reductase and showed that vitamin C levels can be increased in Arabidopsis thaliana plants by GalUR overexpression.

"Vitamin C...