Plants' production of vitamin C studied

HANOVER, N.H., May 1 (UPI) -- U.S. researchers reported discovering the biosynthetic pathway by which plants manufacture vitamin C.

UCLA and Dartmouth University scientists who normally work on genes involved in aging and cancer in animals, said the discovery came while they were studying a gene in worms.

"We uncovered the last unknown enzyme in the synthesis of vitamin C in plants," said Charles Brenner of the Dartmouth Medical School's Norris Cotton Cancer Center.

Humans have lost the ability to make vitamin C -- well known as an antioxidant and enzyme cofactor -- and need to take it up from dietary sources, particularly from plants.

Only in 1998 was a biosynthetic pathway proposed to explain how plants make vitamin C. Research since then confirmed much of the pathway, although the gene responsible for the seventh step of the proposed 10-step pathway from glucose to vitamin C remained unknown.

The new research by Brenner and UCLA's Steven Clarke led to the discovery.

The findings are detailed in the Journal of Biological Chemistry.