Navigation Links
Cornell researchers prove how plants transport sugars
Date:12/21/2007

How do many plants ship sugars from their leaves to flowers, roots, fruits and other parts of their structure? Using genetic engineering techniques, Cornell researchers have finally proven a long-standing theory of how this occurs.

The findings not only deepen understanding of basic plant biology but could one day allow researchers to genetically engineer plants with increased photosynthetic rates, yields and carbon dioxide intake. This might be critically important in an era of climate change.

The theory of transporting sugar, the polymer trap model, was first proposed in 1991 by Robert Turgeon, Cornell professor of plant biology. He is also the senior author of the latest research published in the Dec. 4 issue of the Proceedings of the National Academy of Sciences. Ashlee McCaskill, Ph.D. '07, who worked in Turgeon's lab, is the paper's lead author.

Turgeon's theory suggested that as sucrose, a form of sugar, accumulates in leaves as a product of photosynthesis, it diffuses into the plant's tubelike transport tissue, called phloem, along with other nutrients to move to other areas of the plant. Once in the phloem, small molecules of sucrose polymerize, or combine, to form larger, more complex sugars, which become too large to flow back into the leaf. The polymerized sugars are then forced to move away from the leaf to parts of the plant where they may be used or stored.

To prove the theory, Turgeon and McCaskill genetically engineered a plant closely related to a member of the figwort family, purple mullein (Verbascum phoeneceum L.), so that two genes involved with polymerizing sucrose into larger molecules were silenced. When they did so, sugars backed up in the leaves.

In normal plants, when sugars (made from water and carbon dioxide during photosynthesis) accumulate in the leaves, photosynthesis slows down, and the plant does not take in as much carbon dioxide from the air. Likewise, when the sugars move out of the leaves, the rate of photosynthesis and carbon intake increases, McCaskill said.

"If we could increase the plant's phloem-loading rate, the potential would be to increase photosynthetic rate and yield, but that is theoretical right now," said McCaskill.

A 2006 article in the journal Science, McCaskill said, showed that when atmospheric carbon dioxide increases, plants do not take in the excess due to a series of feedback loops that constrain the plant.

"Phloem loading is one of these feedbacks that have an effect on the ability of plants to intake carbon dioxide at the highest level," said McCaskill. Carbon dioxide, which is increasing in the Earth's atmosphere, is the major greenhouse gas that traps heat and warms the planet, McCaskill noted.


'/>"/>

Contact: Press Relations Office
pressoffice@cornell.edu
607-255-6074
Cornell University Communications  
Source:Eurekalert

Related biology news :

1. Cornell will host the Northeast Biofuel Summit, Nov. 11-13
2. First symposium of UN University-Cornell Africa Series to be held at UN
3. Wiggle room: Cornell researcher borrows idea from sperm to provide energy for nanoscale robots
4. Drug aimed at 2 bioterror agents blocks live viral infection, Weill Cornell team reports
5. Cornell researcher seeks clues to how tuberculosis infects cells
6. Researchers identify proteins involved in new neurodegenerative syndrome
7. Texas researchers and educators head for Antarctica
8. MGH researchers describe new way to identify, evolve novel enzymes
9. University of Pennsylvania researchers develop formula to gauge risk of disease clusters
10. U of MN researchers discover noninvasive diagnostic tool for brain diseases
11. U of Minnesota researchers discover noninvasive diagnostic tool for brain diseases
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Cornell researchers prove how plants transport sugars
(Date:10/4/2017)...  GCE Solutions, a global clinical research organization (CRO), announces the ... on October 4, 2017. Shadow is designed to assist medical writers ... 0070 of the European Medicines Agency (EMA) in meeting the requirements ... ... ...
(Date:6/30/2017)... , June 30, 2017 Today, ... developer and supplier of face and eye tracking ... Featured Product provider program. "Artificial ... innovative way to monitor a driver,s attentiveness levels ... from being able to detect fatigue and prevent ...
(Date:5/16/2017)... May 16, 2017  Veratad Technologies, LLC ( www.veratad.com ... age and identity verification solutions, announced today they will ... 2017, May 15 thru May 17, 2017, in ... International Trade Center. Identity impacts the ... in today,s quickly evolving digital world, defining identity is ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... The Blavatnik Family ... and six Finalists of the 2017 Blavatnik Regional Awards for Young Scientists. ... and administered by the New York Academy of Sciences to honor the excellence ...
(Date:10/12/2017)... ... October 12, 2017 , ... AMRI, ... and biotechnology industries to improve patient outcomes and quality of life, will now ... testing are being attributed to new regulatory requirements for all new drug products, ...
(Date:10/11/2017)... ... ... a basic first aid supply for any work environment, but most personal eye wash can ... a dangerous substance enters both eyes? It’s one less decision, and likely quicker response time ... , “Whether its dirt and debris, or an acid or alkali, getting anything in your ...
(Date:10/11/2017)... the Netherlands and LAGUNA HILLS, Calif. ... The Institute of Cancer Research, London ... use MMprofiler™ with SKY92, SkylineDx,s prognostic tool to risk-stratify patients ... trial known as MUK nine . The University of ... trial, which is partly funded by Myeloma UK, and ICR ...
Breaking Biology Technology: