Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

NC State Geneticists Study Origin, Evolution of "Sticky" Rice

23.10.2002


When tested in iodine, grains of non-glutinous rice turn black (left), while glutinous rice remains unstained.


A study by two North Carolina State University geneticists traces the origin and evolution of a genetic mutation that long ago led to the creation of a type of rice known as glutinous, or "sticky," rice.

The molecular genetic research leads researchers to believe that glutinous rice - which differs from non-glutinous, or common, rice on account of a mutation in its Waxy gene that suppresses the formation of a starch called amylose - most likely originated a single time in Southeast Asia. Further, DNA evidence - namely the lower-than-expected genetic variability in the Waxy gene - suggests that early domesticators of glutinous rice liked its adhesive quality and wanted to preserve that particular trait.

Dr. Michael Purugganan, associate professor of genetics, and Dr. Kenneth Olsen, post-doctoral research associate in genetics, publish their findings in the Oct. 23 edition of Genetics.



To learn more about the origin and evolution of sticky rice, the researchers studied 105 glutinous and non-glutinous samples of rice donated from the multitudinous stock kept by the International Rice Research Institute in Los Banos, Philippines.

Rice contains two starches: amylose and amylopectin. Glutinous rice lacks amylose; in fact, it is the lack of amylose that gives it its sticky composition. Non-glutinous rice - what you’d find if you cooked up a name-brand package of rice from the grocery store, for example - contains up to 30 percent amylose; the result is rice with grains that separate.

Glutinous rice is the staple food in some areas in Southeast Asia, including parts of Laos, Thailand and Cambodia, the researchers say. Sticky rice has also migrated north to become an important part of the diet in places like China and Japan. Used primarily in a number of desserts - rice cakes, for example - sticky rice has achieved important cultural standing in East and Southeast Asia.

But Asian folklore diverges on the origin of glutinous rice, Purugganan says. He found both a Laotian Buddhist legend charting the existence of glutinous rice to about 1,100 years ago and Chinese folklore that indicated the existence of glutinous rice more than 2,000 years ago.

"Since no one really knows where glutinous rice came from, we wanted to find its origin using molecular means," Purugganan says. "We also wanted to find out the number of times the mutation in the Waxy gene that suppresses amylose, which produces glutinous rice, arose during rice domestication. And, we wanted to see if the Waxy gene showed evidence of selection by early Asian farmers."

Performing genetic sequencing of these samples at NC State’s Genome Research Laboratory, Purugganan and Olsen assembled a "gene tree," or network that represents patterns of genetic differences among the DNA sequences, Olsen explains.

Using the gene tree, the researchers found that sticky rice’s genetic mutation maps to a single mutation on the gene tree, suggesting that the mutation occurred a single time rather than more than once, Olsen says. Looking at the geographic locations of the rice DNA sequences that are direct ancestors of the mutation, the researchers found fairly strong evidence that Southeast Asia was the geographic origin of sticky rice. This squares with the fact that sticky rice is a staple in some parts of Southeast Asia.

"This type of research really opens up the window of not only how crops originate, but also how specific features evolve," Purugganan says. Olsen adds, "This is one of the first times that anyone has looked within a crop species at the evolutionary and geographical origins of important domestication traits in crops."

Purugganan and Olsen now plan to study other genes involved in starch synthesis in rice.

Research funding for the study of the origin and evolution of glutinous rice was provided
by the Alfred P. Sloan Foundation.

Dr. Michael Purugganan | North Carolina State University

More articles from Life Sciences:

nachricht New candidate for raw material synthesis through gene transfer
02.07.2020 | Karlsruher Institut für Technologie (KIT)

nachricht Marine alga from the Kiel Fjord discovered as a remedy against infections and skin cancer
02.07.2020 | Helmholtz Centre for Ocean Research Kiel (GEOMAR)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

Im Focus: A structural light switch for magnetism

A research team from the Max Planck Institute for the Structure of Dynamics (MPSD) and the University of Oxford has managed to drive a prototypical antiferromagnet into a new magnetic state using terahertz frequency light. Their groundbreaking method produced an effect orders of magnitude larger than previously achieved, and on ultrafast time scales. The team’s work has just been published in Nature Physics.

Magnetic materials have been a mainstay in computing technology due to their ability to permanently store information in their magnetic state. Current...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

 
Latest News

The lightest electromagnetic shielding material in the world

02.07.2020 | Materials Sciences

Spintronics: Faster data processing through ultrashort electric pulses

02.07.2020 | Information Technology

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>