Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Canola study solves seed oil mystery

09.12.2004


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."

Jörg Schwender | EurekAlert!
Further information:
http://www.msu.edu

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>