Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Devastating parasitic weed may be felled by toxin borrowed from flies

30.03.2004


The parasitic weed, broomrape, attaches to the root of such vegetable crops as tomato, potato, beans, and sunflowers. With no need for leaves of its own, it produces only a floral shoot above ground. Meanwhile, its host is barely able to survive, much less be productive.



Now, the defense mechanism of another pest – the fly – may provide a weapon against parasitic weeds.

Researchers from Virginia Tech in the United States and the Agricultural Research Organization (ARO) of Israel will likely create a buzz of fascination when they present their results at the 227th national meeting of the American Chemical Society in Anaheim, Calif., March 28-April 1.


Broomrape is very disruptive throughout the Middle East and Africa, as well as in some parts of Europe. Plant breeders have been trying for decades to breed crops that will resist the weed. Genetic engineering to create resistant crops is the latest strategy.

Egyptian broomrape, or Orobanche aegyptiaca, was certainly a logical target for the efforts of Noureddine Hamamouch of Morocco, a doctoral student in plant pathology, physiology, and weed science (PPWS) at Virginia Tech. And genetic engineering was the logical strategy. But the toxin he decided to experiment with, an antibacterial peptide that is part of the defense arsenal of the flesh fly (Sarcophaga peregrina), was a matter of luck, says PPWS professor James Westwood.

Westwood’s colleague, Radi Aly, of the weed science department at Newe Ya’ar Research Center of ARO had been working with the fly peptide, sarcotoxin as part of another, unrelated project. "He had it on hand and just tried it to see what would happen."

The model plant for the research is tobacco, which Virginia Tech researchers have used for other transgenic projects. At around the time Aly realized he had a potential toxin in hand, Westwood’s group had just identified a gene promoter that switched on specifically in response to the parasite. The two groups joined forces to maximize the impact of their strategy.

Hamamouch and Aly linked the parasite-induced promoter to the sarcotoxin gene and introduced the final product into the tobacco genome using Agrobacterium-mediated transformation. The introduced gene was thus silent in the healthy tobacco plant but turned on when it sensed an invading parasite.

But would Egyptian broomrape be repelled by this souped-up off shoot of an antibacterial peptide from a flesh fly? Yes.

But the results are somewhat uneven. In some instances, the broomrape planted with the treated tobacco perished. In other instances, it faltered to different degrees, while the host plant produced better than untreated tobacco that was also sharing space with broomrape.

The researchers have also demonstrated that broomrape does suck up macromolecules far bigger than the sarcotoxin peptide along with water and nutrients from the host. "We suspect the toxin moves into the parasite and disrupts its growth," says Westwood.

The goal now is to determine how the new peptide works and how to make it more effective. "We think we need higher levels of expression to get complete resistance. We think that the peptide degrades rapidly, so we need to stabilize it so it lasts longer."

The effectiveness of a fly-defense antibacterial peptide is not entirely serendipity. Westwood explains that flies must have defense systems to protect themselves from microbes – considering their life styles. "They carry defenses with a broad spectrum of activity. Sarcotoxin attacks the membranes of many different bacteria, but is relatively safe for higher organisms. It is interesting that it also is effective against parasitic plants and we want to understand the mechanism."

Why doesn’t it also attack the host? The researchers demonstrated that the toxin is produced only where the parasite attacks the host. "It is produced at the injury site in great numbers and the parasite is like a vacuum cleaner – taking in as much as it can. So it accumulates more of the peptide than remains with the host."

The paper, "Engineering crop resistance to parasitic weeds (AGFD 28)" will be presented by Westwood at 9:20 a.m. Monday, March 29, as part of the symposium on natural products for pest management at 8:15 a.m. to 12:30 p.m., in the Hilton’s Pacific Ballroom B. Authors are Hamamouch, Aly, Virginia Tech PPWS professor Carole L. Cramer, and Westwood.



Contact for more information:
Dr. Noureddine Hamamouch, who has received his PhD. from Virginia Tech, nhamamou@vt.edu
Dr. James L. Westwood at Virginia Tech, westwood@vt.edu, 540-231-7519
Dr. Radi Aly, Newe Ya’ar Research Center, ARO, radi@volcani.agri.gov.il, 972-4-6539514

Susan Trulove | EurekAlert!
Further information:
http://www.technews.vt.edu/

More articles from Agricultural and Forestry Science:

nachricht New study shows producers where and how to grow cellulosic biofuel crops
17.01.2018 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

nachricht Robotic weeders: to a farm near you?
10.01.2018 | American Society of Agronomy

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>