Featured Research

from universities, journals, and other organizations

Canola Study Solves Seed Oil Mystery

Date:
December 9, 2004
Source:
Michigan State University
Summary:
Scientists from Michigan State University have uncovered a previously unknown metabolic mechanism used by plants to create seed oil.

EAST LANSING, Mich. – Scientists from Michigan State University have uncovered a previously unknown metabolic mechanism used by plants to create seed oil.

The results, described Wednesday in the British journal Nature, address a longstanding question in plant biology – why do oilseed plants rely on a seemingly inefficient metabolic process to produce such prodigious amount of energy-rich oil? The answer, according to the MSU team, is that plant seeds are more efficient than anyone thought.

"Seeds achieve this high efficiency by using long-known biochemical reactions that are combined in an unconventional way, which had not been expected by biochemists," said Jörg Schwender, MSU plant biology professor and lead author of the study.

The researchers studied canola (or rapeseed), an annual crop in the mustard family that is widely cultivated throughout the upper Midwest, Canada, Europe and Asia. The oil extracted from the seeds of this plant is used to make everything from margarine to industrial lubricants.

Seeds store large oil reserves to use as energy to germinate and grow. In canola, for example, oil can comprise half of the seed's weight.

The rise of modern biochemistry over the last few decades has increased interest in making quantitative descriptions of plants and animals' biochemical reactions.

When it came to canola, the biochemical balance sheet just didn't add up. As far as researchers could tell, the seeds were relying on a creaky and inefficient pathway to produce their sought-after oil.

All plants employ carbon from carbon dioxide to make organic biomass compounds such as sugars, oils and proteins in stems, leaves and flowers.

To harvest carbon from the air, plants go to lots of trouble to convert carbon dioxide into simple sugars. When canola subsequently transformed these sugars into oils, the plants appeared to cough up lots of the carbon dioxide back into the atmosphere.

The chemical reaction appeared to follow the same backwards logic as a person who toils all day on the job to earn $100, only to buy a $5 sandwich and give the remainder of his paycheck back to his employer.

In its experiment, the MSU team tagged carbon atoms and tracked how they were processed by developing canola seeds.

During the conversion of sugars to oils, researchers expected to see the tagged carbon go through a step-by-step series of chemical reactions known as glycolysis, used by all plants and animals to turn sugar into energy and cellular building blocks. This energy, in turn, is used to link the carbon building blocks into molecules of oil.

Instead, the scientists observed an enzyme called Rubisco providing a more efficient pathway to convert sugar to carbon chains for oil. And the pathway involved lots less coughing up of carbon dioxide.

Scientists have long known that in the process of photosynthesis, Rubisco is the key enzyme that captures atmospheric carbon dioxide for conversion into sugars.

However, the MSU team was surprised to see Rubisco – the enzyme's shorthand stands for ribulose bisphosphate carboxylase/oxygenase – also acting as a key agent producing oil in the seed.

In fact, in terms of metabolic heavy-lifting, Rubisco appeared to be much more efficient than glycolysis. The newly uncovered Rubisco bypass pathway produced 20 percent more of the carbon-chain building blocks to make oil while losing 40 percent less carbon dioxide than is lost during glycolysis.

The results cast new light on the seemingly well-understood protein Rubisco, which accounts for 50 percent of a plant's total protein content and is likely the mostly abundant protein on Earth.

Through its role in the snatching carbon atoms from atmospheric carbon dioxide, Rubisco has been recognized as the main chemical gateway for carbon to enter the biosphere. The new findings suggest that Rubisco also gives plants a way to greatly reduce losses back to the atmosphere while they're synthesizing oil.

"Understanding the pathways plants use to make oil will help us to develop new crop varieties with greater oil content," said co-author John Ohlrogge, MSU distinguished professor of plant biology and Michigan Agricultural Experiment Station scientist. "And this becomes especially important as the world depletes its supplies of petroleum."

###

This research is supported in part by the Michigan Agricultural Experiment Station. The MAES is one of the largest research organizations at Michigan State University. Founded in 1888, the MAES funds the work of nearly 400 scientists in five colleges at MSU to enhance agriculture, natural resources and families and communities in Michigan.


Story Source:

The above story is based on materials provided by Michigan State University. Note: Materials may be edited for content and length.


Cite This Page:

Michigan State University. "Canola Study Solves Seed Oil Mystery." ScienceDaily. ScienceDaily, 9 December 2004. <www.sciencedaily.com/releases/2004/12/041208234805.htm>.
Michigan State University. (2004, December 9). Canola Study Solves Seed Oil Mystery. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2004/12/041208234805.htm
Michigan State University. "Canola Study Solves Seed Oil Mystery." ScienceDaily. www.sciencedaily.com/releases/2004/12/041208234805.htm (accessed September 2, 2014).

Share This




More Plants & Animals News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

We've Got Mites Living In Our Faces And So Do You

We've Got Mites Living In Our Faces And So Do You

Newsy (Aug. 30, 2014) — A new study suggests 100 percent of adult humans (those over 18 years of age) have Demodex mites living in their faces. Video provided by Newsy
Powered by NewsLook.com
Washington Wildlife Center Goes Nuts Over Baby Squirrels

Washington Wildlife Center Goes Nuts Over Baby Squirrels

Reuters - US Online Video (Aug. 30, 2014) — An animal rescue in Washington state receives an influx of orphaned squirrels, keeping workers busy as they nurse them back to health. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Experimental Ebola Drug ZMapp Cures Lab Monkeys Of Disease

Newsy (Aug. 29, 2014) — In a new study, a promising experimental treatment for Ebola managed to cure a group of infected macaque monkeys. Video provided by Newsy
Powered by NewsLook.com
Killer Amoeba Found in Louisiana Water System

Killer Amoeba Found in Louisiana Water System

AP (Aug. 28, 2014) — State health officials say testing has confirmed the presence of a killer amoeba in a water system serving three St. John the Baptist Parish towns. (Aug. 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins