Genetic engineering tool generates antioxidant-rich purple rice

June 27, 2017

Researchers in China have developed a genetic engineering approach capable of delivering many genes at once and used it to make rice endosperm--seed tissue that provides nutrients to the developing plant embryo--produce high levels of antioxidant-boosting pigments called anthocyanins. The resulting purple endosperm rice holds potential for decreasing the risk of certain cancers, cardiovascular disease, diabetes, and other chronic disorders. The work appears June 27th in the journal Molecular Plant.

"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."

To date, genetic engineering approaches have been used to develop rice enriched in beta-carotene and folate, but not anthocyanins. Although these health-promoting compounds 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.

To address this challenge, Liu and his colleagues first set out to identify the genes required to engineer anthocyanin production in the rice endosperm. To do so, they analyzed sequences of anthocyanin pathway genes in different rice varieties and pinpointed the defective genes in japonica and indica subspecies that do not produce anthocyanins.

Based on this analysis, they developed a transgene stacking strategy for expressing eight anthocyanin pathway genes specifically in the endosperm of the japonica and indica rice varieties. The resulting purple endosperm rice had high anthocyanin levels and antioxidant activity in the endosperm. "This is the first demonstration of engineering such a complex metabolic pathway in plants," Liu says.

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.
-end-
This work was supported by grants from National Natural Science Foundation of China, the Ministry of Agriculture of China, and Guangdong Province Public Interest Research and Capacity Building Special Fund 636.

Molecular Plant, Zhu et al.: "Development of ''Purple Endosperm Rice'' by Engineering Anthocyanin Biosynthesis in the Endosperm with a High-Efficiency Transgene Stacking System" http://www.cell.com/molecular-plant/abstract/S1674-2052(17)30140-5

Molecular Plant, published by Cell Press for the Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, and Chinese Society of Plant Biology, is a monthly journal that focuses broadly on plant science, including cellular biology, physiology, biochemistry, molecular biology, genetics, development, plant-microbe interaction, genomics, bioinformatics, and molecular evolution. All contents are freely available starting 12 months after publication. Visit: http://www.cell.com/molecular-plant. To receive Cell Press media alerts, contact press@cell.com.

Cell Press

Related Cardiovascular Disease Articles from Brightsurf:

Changes by income level in cardiovascular disease in US
Researchers examined changes in how common cardiovascular disease was in the highest-income earners compared with the rest of the population in the United States between 1999 and 2016.

Fighting cardiovascular disease with acne drug
Researchers from the European Molecular Biology Laboratory (EMBL) in Heidelberg and Stanford University have found the cause of dilated cardiomyopathy - a leading cause of heart failure - and identified a potential treatment for it: a drug already used to treat acne.

A talk with your GP may prevent cardiovascular disease
Having a general practitioner (GP) who is trained in motivational interviewing may reduce your risk of getting cardiovascular disease.

Dilemma of COVID-19, aging and cardiovascular disease
Whether individuals should continue to take angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in the context of coronavirus disease 2019 (COVID-19) is discussed in this article.

Air pollution linked to dementia and cardiovascular disease
People continuously exposed to air pollution are at increased risk of dementia, especially if they also suffer from cardiovascular diseases, according to a study at Karolinska Institutet in Sweden published in the journal JAMA Neurology.

New insights into the effect of aging on cardiovascular disease
Aging adults are more likely to have - and die from - cardiovascular disease than their younger counterparts.

Premature death from cardiovascular disease
National data were used to examine changes from 2000 to 2015 in premature death (ages 25 to 64) from cardiovascular disease in the United States.

Ultrasound: The potential power for cardiovascular disease therapy
In the current issue of Cardiovascular Innovations and Applications volume 4, issue 2, pp.

Despite the ACA, millions of Americans with cardiovascular disease still can't get care
Cardiovascular disease (CVD) is the leading cause of death for Americans, yet millions with CVD or cardiovascular risk factors (CVRF) still can't access the care they need, even years after the implementation of the Affordable Care Act (ACA).

Excess weight and body fat cause cardiovascular disease
In the first Mendelian randomization study to look at this, researchers have found evidence that excess weight and body fat cause a range of heart and blood vessel diseases (rather than just being associated with it).

Read More: Cardiovascular Disease News and Cardiovascular Disease Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.