Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Wheat can fatally starve insect predators

15.01.2007
A newly identified wheat gene produces proteins that appear to attack the stomach lining of a crop-destroying fly larvae so that the bugs starve to death.

The gene's role in creating resistance to Hessian flies was a surprise to U.S. Department of Agriculture and Purdue University researchers, discoverers of the gene and its function. They made the finding as they investigated new, long-term methods to protect wheat from insect damage.

"This is a different kind of defense than we were expecting," said Christie Williams, a USDA-Agricultural Research Service scientist and Purdue Department of Entomology adjunct assistant professor. "Usually we expect the plant to fortify its cell walls or make poisons to use against insects and pathogens."

Instead, the researchers found that a specific protein, called HFR-3, one of a group of substances called lectins, is capable of binding with a carbohydrate complex in the Hessian fly larvae. The lectin acts as a key to the carbohydrate structure, known as a chitin.

When the larvae attack a resistant plant, the plant's lectin production quickly increases by as much as 3,000 times. The larvae then ingest the lectin. This interaction probably damages the larvae's chitin-rich mid-gut lining so that it can't absorb nutrients from the plant, causing the insects starve, Williams said.
... more about:
»Hessian »Williams »larvae »lectin »starve »virulent

Some Hessian fly larvae, which are called virulent, are capable of ridding their bodies of lectin and surviving. Avirulent larvae are unable to deactivate the lectin.

However, the researchers believe that plants resistant to Hessian fly invasions may make several strains of lectins in response to virulent larvae, Williams said.

Results of the study are published in the January issue of the journal Molecular Plant Pathology.

Researchers also discovered that not only do lectins damage the insect's mid-stomach, the lectins also taste bad and have some toxicity.

"By studying these different wheat genes, we're starting to put together a bigger picture of how Hessian fly–wheat interactions trigger resistance in the plant," Williams said. "We think that some of this has to do with the plant producing enough lectin that it just becomes so unpalatable that the insects can't feed and they starve to death."

Wheat plants that produce few or no lectins that bind to chitin are susceptible to Hessian fly larvae attack, she said. In addition, some virulent larvae can reprogram plant development so that cells in leaves and the base of the plant where the insects feed pump out nutrients favored by the insect. If this happens then even the weak, avirulent larvae on the same leaf have a chance to survive.

The researchers discovered that Hessian fly larvae reprogramming of resistant plant cells only occurs at sites where the insects attack. The study also revealed that increased numbers of larvae on a plant caused a parallel increase in lectin. This shows that wheat plant responses to these insects are localized and take less energy than a more global resistance response.

"Figuring out some of the ways that a plant is able to respond to insects with resistance will be useful in crop breeding programs," Williams said. "We're finding compounds like this chitin-binding lectin that don't cost the plant much to produce, unlike producing poisons and stronger walls. Those inducible defenses use a lot of a plant's energy that could be used toward growth and reproduction."

The scientists currently are looking for regulatory regions in Hessian fly-susceptible wheat genes that might act as vehicles to carry lectin or a toxin into plants to halt the virulent insects, Williams said. The regulatory regions, or promoters, would be from genes that the fly larvae ordinarily manipulate so plants will produce useful nutrients for the insect. Instead, the promoter would be hooked up to a lectin or toxin gene and inserted into the cells. When larvae manipulate the promoter, they would receive gut-altering lectin instead of nutrients.

To advance their investigation into developing more resistant plants, the researchers are beginning work on a single microchip that would be an array of genes from both the Hessian fly and wheat. This will allow the scientists to study insect-plant interactions. Knowing the timing and location of those interactions would enable the scientists to use the promoter tactic only in the vegetative parts of the wheat plant rather than in the head or grain portions. This will protect the grain quality and the consumer.

"Once we understand which genes are active and the timing of the interactions, we can really understand what the insect says to the plant and how the plant responds," Williams said.

The Hessian fly, which German mercenaries apparently introduced into North America during the Revolutionary War, causes catastrophic losses if not controlled by resistant plants. During the 1980s the state of Georgia suffered $28 million in lost wheat in one year after the fly overcame the plants' resistance gene used in the area at the time.

The Hessian fly is particularly insidious because it actually can control the wheat plant's development.

The adult fly lays eggs on the plant leaves. After the eggs hatch, the resulting tiny, red larvae crawl down to the base of the wheat where they feed on the plant. If the plant isn't resistant to the insect, the larvae inject chemicals from their saliva into the plant that completely alter the wheat's physiology and growth.

The other researchers on this study were USDA postdoctoral students Kurt Saltzmann and David Puthoff, Purdue graduate students Marcelo Giovanini and Martin Gonzalo, and Purdue professor of agronomy Herbert Ohm.

The USDA Agricultural Research Service Crop Production and Pest Control Research Unit and the Ministry of Education of Brazil CAPES Programme provided support for the study.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Source: Christie Williams, (765) 494-6753, cwilliams@purdue.edu

Ag Communications: (765) 494-2722;
Beth Forbes, forbes@purdue.edu
Agriculture News Page

Susan A. Steeves | EurekAlert!
Further information:
http://www.purdue.edu

Further reports about: Hessian Williams larvae lectin starve virulent

More articles from Life Sciences:

nachricht Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>