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 Faba fix for corn's nitrogen need
11.04.2018 | American Society of Agronomy

nachricht Wheat research discovery yields genetic secrets that could shape future crops
09.04.2018 | John Innes Centre

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: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

Im Focus: Like a wedge in a hinge

Researchers lay groundwork to tailor drugs for new targets in cancer therapy

In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Magnetic nano-imaging on a table top

20.04.2018 | Physics and Astronomy

Start of work for the world's largest electric truck

20.04.2018 | Interdisciplinary Research

Atoms may hum a tune from grand cosmic symphony

20.04.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>