Featured Research

from universities, journals, and other organizations

Simple Sugars Make Cell Walls Like Steel

Date:
January 21, 2004
Source:
Purdue University
Summary:
Simple sugars apparently are the biological signals needed to maintain the steel-like strength of plant cell walls, according to Purdue University scientists.

Purdue researcher Nick Carpita uses Arabidopsis plants grown in this growth chamber at Purdue's Hansen Life Sciences Research Building to determine what makes some plant cell walls as strong as steel. (Purdue Agricultural Communications photo/Tom Campbell)

WEST LAFAYETTE, Ind. - Simple sugars apparently are the biological signals needed to maintain the steel-like strength of plant cell walls, according to Purdue University scientists.

"This is a really fundamental discovery in the mechanics of plant growth that eventually could have several practical applications," said Nick Carpita, a botany and plant pathology professor. "These could include controlling crop plant size and shape, improving desirable textural properties of fruits and vegetables, and enhancing nutritional fibers in plant cell walls without changing other plant structural factors."

Before these goals can be accomplished, however, the scientists must learn as much as possible about how plant cell walls are created and evolve, he said.

Plant cell walls are composites of minute plant fibers interlaced with many different chains of simple sugars, or polymers, that make the structure strong, Carpita said. While studying how cell walls change as plants develop, his research team discovered that an enzyme requires a simple milk sugar, called galactose, to relace polymers during growth.

The scientists report their findings in the January issue of the journal Plant Physiology.

"A plant cell is essentially concentric rings or spools of cellulose, so when the cells expand, the microfibrils of the wall spread apart," Carpita said. "New microfibrils, or minute organic plant fibers, that are synthesized during growth are continually integrated from the inner rings into the outer rings.

"This process prevents the thickness of the wall from changing even as the cell increases 100 or 1,000 times its length."

The galactose needed to ensure wall strength during plant cell growth is attached to some long polymers, he said. However, abnormal plants, or mutants, that are missing the simple sugars lose cell wall tensile strength.

Xyloglucan, a sugar polymer that has several molecules of simple sugars, ties the spools of cellulose together, he said. An enzyme called xyloglucan endo-transglucosylase, or XET, breaks the tether during cell growth to allow the microfibrils to separate. However, XET hangs onto one end of the broken polymer so when a new cellulose fibril forms to fill the space, the enzyme brings old and new xyloglucans together to relace the cellulose to maintain tensile strength. This process not only allows the cell wall to grow, but also is the way growth is finally halted.

"When the plant cells grow, there is a mechanism to loosen the cell walls of the interlacing molecules so the sugar can push those microfibrils apart," Carpita said. "The thickness isn't compromised because new cellulose microfibrils fill the gap. Unless the xyloglucans are retied or reassociated around the new configurations of microfibrils, the cells will continue to expand indefinitely."

Using the common research plant Arabidopsis, the researchers looked at mutants and found some that developed abnormally. The mutants the scientists studied had an area at the base of the embryonic plant stems, called the hypocotyls, that bulged.

"We isolated the enzyme, isolated the individual polymers, and showed that their activity was severely compromised if the simple sugar galactose was missing from the xyloglucan," Carpita said. "In the plant, the consequence is that the tensile strength of the cell walls is less than half of normal.

"They are really flimsy cells and they bulge out. Instead of being really nice and columnar as this tissue usually is, they get a little flabby. We deduced that these galactose appendages are required for XET to recognize where to clip the xyloglucans to allow expansion and then to retie them."

The scientists want to find out how to control cell wall formation by determining the function of all the genes in their formation, development and growth. This may allow them to improve many everyday products from food to chairs.

The other researchers involved in this study are Maria Peña, currently of Complex Carbohydrate Research Center, University of Georgia; and Peter Ryden and Andrew C. Smith, of the Institute of Food Research, Norwich Research Park, Colney, England; and Michael Madson, Lafayette, Ind.

The U.S. Department of Agriculture National Research Initiative Competitive Grants Program and the Biological Sciences Research Council of Great Britain funded this research.

Related Web sites:

Plant Physiology: http://www.plantphysiol.org/

Purdue University cell wall genomics: http://cellwall.genomics.purdue.edu

Purdue Department of Botany and Plant Pathology: http://www.btny.purdue.edu

Nichols Carpita: http://www.btny.purdue.edu/faculty/carpita National Research Initiative: http://www.reeusda.gov/nri/


Story Source:

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


Cite This Page:

Purdue University. "Simple Sugars Make Cell Walls Like Steel." ScienceDaily. ScienceDaily, 21 January 2004. <www.sciencedaily.com/releases/2004/01/040121080120.htm>.
Purdue University. (2004, January 21). Simple Sugars Make Cell Walls Like Steel. ScienceDaily. Retrieved August 30, 2014 from www.sciencedaily.com/releases/2004/01/040121080120.htm
Purdue University. "Simple Sugars Make Cell Walls Like Steel." ScienceDaily. www.sciencedaily.com/releases/2004/01/040121080120.htm (accessed August 30, 2014).

Share This




More Health & Medicine News

Saturday, August 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

3 Things To Know About The Ebola Outbreak's Progression

3 Things To Know About The Ebola Outbreak's Progression

Newsy (Aug. 29, 2014) — Here are three things you need to know about the deadly Ebola outbreak's progression this week. 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
Who Could Be Burnt by WHO's E-Cigs Move?

Who Could Be Burnt by WHO's E-Cigs Move?

Reuters - Business Video Online (Aug. 28, 2014) — The World Health Organisation has called for the regulation of electronic cigarettes as both tobacco and medical products. Ciara Lee looks at the impact of the move on the tobacco industry. Video provided by Reuters
Powered by NewsLook.com
CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

CDC Director On Ebola Outbreak: 'It's Worse Than I Feared'

Newsy (Aug. 28, 2014) — CDC director Tom Frieden says the Ebola outbreak is even worse than he feared. But he also said there's still hope to contain it. Video provided by Newsy
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