They might be called a blessing or a curse -- tannins, which are present in certain sorghums, contain health-promoting antioxidant properties, but also provide a bitter taste and decreased protein digestibility.
To better understand tannins, their role in sorghum and how they can be altered to improve sorghum's use as food and feed, a team of scientists led by Kansas State University and U.S. Department of Agriculture researchers, has cloned the tannin gene in sorghum.
Tannins' high antioxidant, anti-inflammatory and UV-protective functions promote human health, plus recent studies show they can be a tool in fighting obesity because they reduce digestibility, said Jianming Yu, associate professor of agronomy at Kansas State University. Tannins in sorghum also provide a natural chemical defense against bird predation and bacterial and fungal attack in the field.
On the other hand, tannins provide a bitter taste to some foods and decrease protein digestibility and feed efficiency in humans and livestock.
The team was led by Yu, along with Tesfaye Tesso, Kansas State University sorghum breeder and associate professor of agronomy and Scott Bean, scientist with the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) and adjunct faculty in the university's Department of Agronomy.
The researchers' study, "Presence of tannins in sorghum grains is conditioned by different natural alleles of Tannin1" was published in the June 26 issue of the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
Sorghum is an old-world cereal grass that serves as a dietary staple for more than 500 million people in more than 30 countries, Yu said. In 2011, the United States was the No. 1 exporter of sorghum on the world market and the No. 2 producer (behind Nigeria), according to the U.S. Department of Agriculture. In 2011, Kansas produced 110.0 million bushels – 51 percent of the total U.S. crop. Sorghum production in the U.S., primarily for the feed industry, uses non-tannin sorghum hybrids.
Unlike many plants which employ C3 photosynthesis that uses water, carbon dioxide and solar energy to synthesize sugars, sorghum, which performs a modified form called C4 photosynthesis, has adapted to hot environments.
"One key reason to study tannins is to untangle their relationship with cold tolerance, a key agronomic trait to improve sorghum. The work is ongoing," said sorghum breeder Tesso. An earlier screening work found that a high proportion of cold tolerant sorghum lines contain tannins.
"Several other factors make tannins an important research subject," said Bean, noting their antioxidant capacity and relevant health benefits, their natural occurrence in some cereal crops, and their role in sorghum production. "Knowledge of tannins in biosynthesis pathways can be used to generate lines that produce high-content tannins in sorghum and other cereals to promote health through their unique nutritional properties."
This study, like many studies in recent years, benefits from work done several years ago on Arabidopsis, which are small flowering plants related to cabbage and mustard, said Yuye Wu, the first author and Kansas State University research associate of agronomy. "Many genes have been identified in Arabidopsis, through the mutational approach, but there is still much to be learned about the genetic control of tannins in cereal crops."
"This kind of genetic research in crops, coupled with nutritional and medical research, could open the possibility of producing different levels and combinations of phenolic compounds to promote human health," Yu said. What the researchers learn about tannins in sorghum will be beneficial to the future study of tannins in other plants, including some fruits, vegetables and a few other grains such as finger millets and barley.
Other researchers involved in the study were Mitch Tuinstra, Purdue University; Ming Li Wang, USDA-ARS, Griffin, Georgia; and Guihua Bai, USDA-ARS and adjunct professor of agronomy at Kansas State University.
The project was supported by USDA National Institute of Food and Agriculture, Department of Energy Plant Feedstock Genomics Program, National Science Foundation Plant Genome Research Program, USDA Agricultural Research Service, and the National Sorghum Checkoff program.
Jianming Yu | EurekAlert!
Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)
The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
20.10.2017 | Information Technology
20.10.2017 | Materials Sciences
20.10.2017 | Interdisciplinary Research