Scientists develop purple rice that could combat cancer

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Purple rice with the potential to combat cancer and heart disease has been developed by scientists testing a new advance in genetic engineering.

The rice owes its unusual colour to high levels antioxidant-boosting pigments called anthocyanins, which are also found in blueberries and red cabbage.

Its ability to counteract oxidation damage to cells could reduce the risk of certain cancers, cardiovascular disease, diabetes and other chronic disorders, claim the Chinese researchers.

You will not find purple rice in supermarkets any time soon, however. It was only created to demonstrate a new technology that allows many genes to be delivered into a plant at once.

The scientists intend to evaluate the safety of the rice as a biofortified food, and hope to create other "purple" cereals by introducing anthocyanins into seeds.

Previous attempts to engineer anthocyanin production in rice have failed because the underlying biosynthesis pathway is so complex.

The Chinese team found a way to "stack" the eight genes needed for anthocyanin production and activate them in rice "endosperm" - the seed's nutrient providing inner region.

Lead researcher Dr Yao-Guang Liu, from South China Agricultural University, said: "This is the first demonstration of engineering such a complex metabolic pathway in plants.

"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."

The findings are reported in the journal Molecular Plant.

Genetic engineering has already been used to produce rice enriched with the health-giving compounds beta-carotene and folate.

Anthocyanins are naturally present in the outer layers of some black and red rice varieties. But they are absent from polished rice grains which have had their husk, bran and germ (embryo) layers removed, leaving only the endosperm.