CHINA, July 12, 2017 - Purple rice developed by Chinese scientists. A new genetic engineering technique developed by Chinese scientists has been used to develop purple rice packed with antioxidant-boosting pigments called anthocyanins.

A study published in Molecular Plant shows how the scientists created the technique, which is capable of delivering many genes at once, and used it to make rice endosperm – seed tissue that provides nutrients to the developing plant embryo. Although anthocyanins are naturally abundant in some black and red rice varieties, they are absent in polished rice grains because the husk, bran, and germ have been removed, leaving only the endosperm.

Previous attempts to engineer anthocyanin production in rice have failed because the underlying biosynthesis pathway is highly complex, and it has been difficult to efficiently transfer many genes into plants. Genetic engineering approaches have previously been used to develop rice enriched in beta-carotene and folate, but not anthocyanins.

“We have developed a highly efficient, easy-to-use transgene stacking system called TransGene Stacking II that enables the assembly of a large number of genes in single vectors for plant transformation,” says senior study author Yao-Guang Liu of the South China Agricultural University. “We envisage that this vector system will have many potential applications in this era of synthetic biology and metabolic engineering.” The researchers plan to evaluate the safety of purple endosperm rice as biofortified food and will try to engineer the biosynthesis of anthocyanins in other crops to produce more purple endosperm cereals.