Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene guards grain-producing grasses so people and animals can eat

04.02.2008
Purdue University and USDA-Agricultural Research Service scientists have discovered that a type of gene in grain-producing plants halts infection by a disease-causing fungus that can destroy crops vital for human food supplies.

The research team is the first to show that the same biochemical process protects an entire plant family - grasses - from the devastating, fungal pathogen. The naturally occurring disease resistance probably is responsible for the survival of grains and other grasses over the past 60 million years.

The findings will stimulate the design of new resistance strategies against additional diseases in grasses and other plants. Grasses' ability to ward off pathogens is a major concern because grasses, including corn, barley, rice, oats and sorghum, provide most of the calories people consume, and some species also increasingly are investigated for conversion into energy.

A resistance gene, first discovered in corn, and the fungal toxin-fighting enzyme it produces apparently provide a biological mechanism that guards all grass species from this fungus, said Guri Johal, a Purdue associate professor of botany and plant pathology. He is senior and corresponding author of the study published this week (Jan. 28-Feb. 1) in Early Edition, the online version of the Proceedings of the National Academy of Sciences. It will appear in the Feb. 5 print edition.

"We think that if the gene Hm1 had not evolved, then grasses would have had a hard time surviving, thriving or, at least, the geographic distribution would have been restricted," Johal said. "This plant resistance gene is durable and is indispensible against this fungal group, which has the ability to destroy any part of the plant at any stage of development."

In 1943 a related fungus decimated rice crops in Bengal, causing a catastrophic famine in which 5 million people starved. The same fungal group was responsible for the other two recorded epidemics in grasses in the 20th century, including the 1970 southern corn leaf blight that destroyed 15 percent of the U.S. corn crop.

The study, part of an effort to prevent future crop crises, also provides new information about the evolution of plant-pathogen interaction, report Johal and his colleagues, including USDA-Agricultural Research Service researcher Steven Scofield and plant geneticist Michael Zanis. The findings have implications for continued survival and further evolution of grasses, which also include rye, bluegrass, reed canary grass and bamboo.

Johal and the research team began this study because they had a hunch that a genetic mechanism similar to the one protecting corn from a fungus, called Cochliobolus carbonum race 1 (CCR1), might also be at work in other grasses. They knew that all grasses had genes similar, or homologous, to Hm1, but not whether the same genetic mechanism was providing resistance against the fungus and its toxin.

To determine if the same biochemical processes were at work to prevent grass susceptibility to the fungus family, Johal and his team shut off the Hm1 homologue in some barley plants. Next, they infected the test barley with fungus.

In barley that no longer had a functioning Hm1 homologous gene, the fungus, with the help of its toxin, caused disease in the plant. The resulting tissue damage on the barley leaves was typical of maize leaf blight symptoms in corn.

Some of the research barley, which had a functioning Hm1 gene, was inoculated with the fungus. The results showed that the resistance mechanism was the same as the one that prevents the fungus' disease infection in corn.

As in corn, the Hm1-like gene produced an enzyme that disarmed the fungus' disease-causing toxin. The detoxification isolated the infection at the site where the fungus invaded. The research with the barley also showed that, as in corn susceptible to the fungus, infection isolation occurs if the fungus doesn't produce the toxin.

Now that the researchers know that Hm1 homologues in all grasses apparently trigger the same resistance to the fungal family, the next step will be to investigate how the fungal toxin facilitates disease when not degraded by Hm1.

Scofield is a scientist in the Purdue-based USDA-ARS Crop Production and Pest Control Research Unit and a Purdue adjunct assistant professor. Zanis is an assistant professor in the Purdue Department of Botany and Plant Pathology. The other researchers involved in the study were Anoop Sindhu, co-lead author, former botany and plant pathology postdoctoral research assistant and now an Iowa State University assistant scientist; Satya Chintamanani, co-lead author and a postdoctoral research assistant; and Amanda Brandt, a USDA-ARS research technician.

Purdue University, the National Science Foundation and the USDA-Agricultural Research Service provided funding for this research.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu
Sources: Guri Johal, (765) 494-4448, gjohal@purdue.edu
Steven Scofield, (765) 494-3674, scofield@purdue.edu

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

More articles from Agricultural and Forestry Science:

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

nachricht Advance warning system via cell phone app: Avoiding extreme weather damage in agriculture
12.07.2018 | Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V.

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: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>