April 30 : A group of UCLA and Dartmouth researchers have finally found out how plants manufacture Vitamin C. The team discovered it while working on a particular type of gene in worms.

“We were working on an interesting gene in worms,” said Dr. Steven Clarke of the UCLA Molecular Biology Institute and the Department of Chemistry and Biochemistry.

“One insight led to another until we uncovered the last unknown enzyme in the synthesis of vitamin C in plants,” said Dr. Charles Brenner of Dartmouth Medical School’s Norris Cotton Cancer Center and Department of Genetics.

The team discovered a similarity between the worm gene and the product of the VTC2 gene of Arabidopis thaliana, a small roadside plant whose genetics have been well studied before.

Mutations in this plant gene have been previously linked to low levels of vitamin C.

Researchers found that the sequence of the gene in the worm suggested that it is related to a family of genes altered in cancer, termed HIT genes that Brenner studies at Dartmouth.

The team reconstituted in test tubes the long mysterious seventh step in vitamin C synthesis, a reaction they describe as the first committed step.

Researchers liken the first six steps in vitamin C synthesis to a roadmap with multiple possible routes from glucose to a variety of cellular compounds.

The scientists were able to purify the enzyme from the bacteria, and after preparing their own GDP-L-galactose, the team showed that VTC2 is responsible for the long sought seventh step in vitamin C synthesis.

The team has expressed hope that their discovery might lead to new strategies for increasing vitamin C levels in food crops, which could mean more nutritious foods as well as potentially higher crop yields.

The study appears online in the Journal of Biological Chemistry. (ANI)