0820 GMT December 05, 2019
The added health benefits of the new rice came from high levels of anthocyanins, a group of antioxidant-boosting pigments that also provide the purple, red or blue colors of many fruits and vegetables, news.xinhuanet.com wrote.
According to the study published in the journal Molecular Plant, "Consumption of rice rich in anthocyanins can benefit human health, decreasing the risk of certain cancers, cardiovascular disease, diabetes and other chronic disorder."
However, previous attempts to engineer anthocyanin production in rice have failed because the underlying biosynthesis pathway is highly complex.
To address this challenge, Yao-Guang Liu of the South China Agricultural University and his colleagues first set out to identify the genes related to anthocyanin production in different rice varieties.
The team also pinpointed the defective genes in japonica and indica, subspecies that do not produce anthocyanins.
Then, the researchers developed what they called 'a highly efficient, easy-to-use transgene stacking system' and used it to insert eight genes needed to produce anthocyanin into the japonica and indica rice varieties.
As expected, the resulting purple rice had high anthocyanin levels and antioxidant activity.
Liu said, "This is the first demonstration of engineering such a complex metabolic pathway in plants."
In the future, the researchers believed that their strategy could be used for the production of many other important nutrients and medicinal ingredients.
The researchers now planned to evaluate the safety of the new purple rice as biofortified food and they will also try to engineer the biosynthesis of anthocyanins in other crops to produce more purple cereals.
Liu said, "Our research provides a high-efficiency vector system for stacking multiple genes for synthetic biology and makes it potentially feasible for engineering complex biosynthesis pathways in the endosperm of rice and other crop plants such as maize, wheat, and barley."