A team of scientists from the University of California, Berkeley, has discovered a missing link in the process by which plants make vitamin C. The finding, published in the journal _Nature Plants_, could lead to new ways to increase the vitamin C content of crops and improve human nutrition.

Vitamin C is an essential nutrient for humans and other animals. It is involved in a number of important bodily functions, including immune system support, collagen production, and iron absorption. Plants make vitamin C through a series of chemical reactions that start with the amino acid L-galactose. Previous research had identified some of the enzymes involved in this process, but there was a gap in our understanding of how L-galactose is converted into vitamin C.

The Berkeley team, led by plant biologist Jennifer Lunn, used a combination of biochemical and genetic techniques to identify the missing enzyme. They found that the enzyme, which they named L-galactose dehydrogenase (LGDH), is responsible for converting L-galactose into L-ascorbic acid, the active form of vitamin C.

"The discovery of LGDH is a significant breakthrough in our understanding of how plants make vitamin C," said Lunn. "This finding provides a potential target for genetic engineering to increase the vitamin C content of crops."

The researchers also found that LGDH is regulated by a number of environmental factors, including light and temperature. This suggests that plants may be able to adjust their vitamin C production in response to changing conditions.

"Our findings could lead to new ways to improve the nutritional value of crops and help people around the world get the vitamin C they need," said Lunn.

Vitamin C deficiency is a major problem in many parts of the world. It can lead to a number of health problems, including scurvy, anemia, and impaired immune function. Increasing the vitamin C content of crops could help to reduce these problems and improve public health.