Featured Research

from universities, journals, and other organizations

Changing Climate Likely To Make 'Super Weed' Even More Powerful

Date:
June 4, 2009
Source:
University of Delaware
Summary:
Researchers have discovered a new reason why the tall, tasseled reed Phragmites australis is one of the most invasive plants in the United States. The research team found that Phragmites delivers a one-two chemical knock-out punch to snuff out its victims, and the poison becomes even more toxic in the presence of the sun's ultraviolet rays.

Harsh Bais (left), UD assistant professor of plant and soil sciences, and Thimmaraju Rudrappa, a former UD postdoctoral researcher who is now a research scientist at DuPont, examine specimens of Phragmites.
Credit: Image courtesy of University of Delaware

Researchers at the University of Delaware have discovered a new reason why the tall, tasseled reed Phragmites australis is one of the most invasive plants in the United States.

The UD research team found that Phragmites delivers a one-two chemical knock-out punch to snuff out its victims, and the poison becomes even more toxic in the presence of the sun's ultraviolet rays.

The study, which is published in the June issue of the scientific journal Plant Signaling & Behavior, is believed to be the first to report the effects of UV-B radiation on plant allelopathy, the production of toxins by a plant to ward off encroachment by neighboring plants.

The authors include Thimmaraju Rudrappa, a former postdoctoral researcher at UD who is now a research scientist at the DuPont Company; Harsh Bais, assistant professor of plant and soil sciences; Yong Seok Choi, postdoctoral researcher in the Department of Chemical Engineering; Delphis Levia and David R. Legates, both associate professors in the Department of Geography; and Kelvin Lee, Gore Professor of Engineering and director of the Delaware Biotechnology Institute.

The research was conducted in Delaware wetlands and in Bais's lab at the Delaware Biotechnology Institute, a major center for life sciences research at the University of Delaware.

“The toxin secreted by Phragmites is degraded by sunlight -- ultraviolet rays -- and causes severe deleterious effects on other native plants,” Bais said.

“Our research also addresses the growing questions of increased UV-B incidences because of global warming and its ultimate effect on plants. In this case, an invasive plant is accidentally utilizing the changed global conditions for its survival and invasion,” Bais noted.

Two years ago, Bais led a study which discovered that Phragmites actively secretes gallic acid to kill off plants and take over new turf. Gallic acid, also known as 3,4,5-trihydroxybenzoic acid, is used for tanning leather, making dyes and inks, and formulating astringents, among other applications.

In this research, the scientists found that the gallic acid released by Phragmites is degraded by ultraviolet light to produce another toxin, mesoxalic acid, effectively hitting susceptible plants and seedlings with a double-whammy.

The mesoxalic acid triggers a similar “cellular death cascade” in victim plants as gallic acid does, Bais said, destroying the tubulin and actin, the structural protein in the roots, within minutes of exposure.

The scientific team detected the biological concentrations of mesoxalic acid in Delaware wetlands, in stands of both exotic and native Phragmites australis. The study highlights the persistence of the photo-degraded phytotoxin, particularly potent in the exotic species of the plant, and its enhanced effects against the native species of Phragmites, which is becoming increasingly endangered in the United States.

Walnut trees, pine trees, ferns and sunflowers are among the plants that release harmful chemicals to prevent other plants from growing too close to them.

However, Phragmites uses this strategy not so much to keep other plants away, but to aggressively conquer them and invade new territory, Bais said.

Funding for the project was provided by the University of Delaware Research Foundation.


Story Source:

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


Journal Reference:

  1. Thimmaraju Rudrappa, Yong Seok Choi, Delphis F. Levia, David R. Legates, Kelvin H. Lee and Harsh P. Bais. Phragmites australis root secreted phytotoxin undergoes photo-degradation to execute severe phytotoxicity. Plant Signaling & Behavior, 2009; 4 (6): 506-513 [link]

Cite This Page:

University of Delaware. "Changing Climate Likely To Make 'Super Weed' Even More Powerful." ScienceDaily. ScienceDaily, 4 June 2009. <www.sciencedaily.com/releases/2009/06/090603131439.htm>.
University of Delaware. (2009, June 4). Changing Climate Likely To Make 'Super Weed' Even More Powerful. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2009/06/090603131439.htm
University of Delaware. "Changing Climate Likely To Make 'Super Weed' Even More Powerful." ScienceDaily. www.sciencedaily.com/releases/2009/06/090603131439.htm (accessed October 23, 2014).

Share This



More Plants & Animals News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Working Mother DIY: Pumpkin Pom-Pom

Working Mother DIY: Pumpkin Pom-Pom

Working Mother (Oct. 22, 2014) How to make a pumpkin pom-pom. Video provided by Working Mother
Powered by NewsLook.com
San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

San Diego Zoo's White Rhinos Provide Hope for the Critically Endangered Species

Reuters - Light News Video Online (Oct. 22, 2014) The pair of rare white northern rhinos bring hope for their species as only six remain in the world. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com
Raw: Bear Cub Strolls Through Oregon Drug Store

Raw: Bear Cub Strolls Through Oregon Drug Store

AP (Oct. 22, 2014) Shoppers at an Oregon drug store were surprised by a bear cub scurrying down the aisles this past weekend. (Oct. 22) Video provided by AP
Powered by NewsLook.com
Family Pleads for Pet Pig to Stay at Home

Family Pleads for Pet Pig to Stay at Home

AP (Oct. 22, 2014) The Johnson family lost their battle with the Chesterfield County, Virginia Planning Commission to allow Tucker, their pet pig, to stay in their home, but refuse to let the board keep Tucker away. (Oct. 22) 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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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