May 27, 2017
Whatever your views are on GMO, there’s no debate that most efforts revolve around increasing the size or abundance of crops. Not so with a project undertaken by Chinese scientists in which genes producing anthocyanins have been engineered into strains of rice. Researchers have developed a method capable of delivering many genes at once and used it to produce high levels of antioxidant-boosting pigments called anthocyanins. The resulting purple rice has the potential for decreasing the risk of certain cancers, cardiovascular disease, diabetes, and other chronic disorders.
"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."
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.
In the future, this transgene stacking vector system could be used to develop plant bioreactors for the production of many other important nutrients and medicinal ingredients. For their own part, the researchers plan to evaluate the safety of purple endosperm rice as biofortified food, and they will also try to engineer the biosynthesis of anthocyanins in other crops to produce more purple endosperm cereals.
"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," Liu says.
Qinlong Zhu, Suize Yu, Dongchang Zeng, Hongmei Liu, Huicong Wang, Zhongfang Yang, Xianrong Xie, Rongxin Shen, Jiantao Tan, Heying Li, Xiucai Zhao, Qunyu Zhang, Yuanling Chen, Jingxing Guo, Letian Chen, Yao-Guang Liu. Development of “Purple Endosperm Rice” by Engineering Anthocyanin Biosynthesis in the Endosperm with a High-Efficiency Transgene Stacking System. Molecular Plant, 2017; DOI: 10.1016/j.molp.2017.05.008