Scientists in New Zealand are a step closer to developing new varieties of fruit and vegetables containing high levels of vitamin C, after they identified the plant gene responsible for regulating its production.
A team at state-owned science company Plant & Food Research found that the addition of a particular enzyme to different varieties of strawberry, potato and tomato plant resulted in fruits and tubers with higher levels of ascorbate, a naturally occurring, organic compound form of vitamin C with antioxidant qualities.
The implications for the fresh produce business could be considerable, with the breakthrough potentially making it possible to develop ascorbate-rich fruit and vegetables that in turn make it easier for consumers to maintain a healthy diet.
In the future, said project director Dr William Laing, it may be possible to get a daily dose of vitamin C from just one potato.
"By understanding how vitamin C levels are controlled in plants, particularly in the edible fruits or tubers, there is potential to develop new varieties of common crops with higher levels of natural vitamin C," he explained.
Results from experiments carried out so far have led Plant & Food Research to conclude that breeding new plant varieties with enough naturally occurring vitamin C to offer the recommended daily amount in one average-sized potato could be possible very soon.
Humans need to ingest vitamin C to ensure healthy cell function in the body, the main source being plants and their fruit.
However, many food sources offer relatively low levels of vitamin C, something which has prompted many people to boost their vitamin C intake with artificial supplements.
"These new varieties would have the potential to reduce vitamin C deficiency in populations with reduced access to fruits and vegetables by allowing them to meet recommended levels through consumption of potatoes and other staple foods," he said.
Laing's team artificially added GDP-galactose phosphorylase – an enzyme which controls plant genes and plays an important part in the production of vitamin C – to different varieties of strawberry, potato and tomato.
The results, published for the first time in the Plant Biotechnology Journal, showed that ascorbate levels could be increased by up to 500 per cent.
According to the study, identification of the gene could also help develop molecular markers that allow Plant & Food Research scientists to identify crops with the genetic potential to produce high levels of vitamin C.
Laing added: "Consumers in many countries, including New Zealand, have concerns about the inclusion of transgenic foods in their diet, so the next challenge is how to use this genetic information to speed up the breeding of new non-transgenic varieties with naturally-high levels of vitamin C."