Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists find gene that protects against potato blight

15.07.2003


Scouring the genome of a wild Mexican potato, scientists have discovered a gene that protects potatoes against late blight, the devastating disease that caused the Irish potato famine.


Potato plants exposed to the pathogen that causes late blight, the disease responsible for the Irish potato famine, soon wither and die (left). The plant on the right has been engineered to resist the devastating disease through incorporation of a gene found in a wild Mexican potato, as part of research by John Helgeson, professor of plant pathology and Jiming Jiang, professor of horticulture and others.
Photo by: courtesy department of plant pathology
Date: July 2003



The discovery of the gene and its cloning by scientists at the University of Wisconsin-Madison was reported today (July 14) in online editions of the Proceedings of the National Academy of Sciences (PNAS).

The identification of the gene, found in a species of wild potato known as ´Solanum bulbocastanum, holds significant potential. All of the varieties now cultivated commercially on more than 1.5 million acres in the United States are highly susceptible to potato late blight, a family of fungal pathogens that wreaks havoc in the field, turning tubers to mush and invariably killing any plant it infects.


"We think this could be very useful," says John Helgeson, a UW-Madison professor of plant pathology, a research scientist with the U.S. Department of Agriculture and a senior author of the PNAS paper. "No potato grown in the United States on any scale at all has resistance to this disease."

With the blight-resistant gene in hand, the Wisconsin team, which also includes Jiming Jiang, a UW-Madison professor of horticulture, was able to engineer plants that survived exposure to the many races of Phytophthora infestans. The insertion of a single gene, according to Jiang and Helgeson, effectively protects plants from the range of late blight pathogens.

"So far, the plants have been resistant to everything we have thrown at them," says Helgeson.

The world’s most serious potato disease, late blight is best known as the cause of the Irish potato famine. Seeming to appear from nowhere in 1845, the fungus wiped out the staple crop of the densely populated island nation, causing mass starvation over five years, killing more than a million people and sparking a wave of immigration that had worldwide social consequences.

More than 150 years later, Ireland’s population has yet to return to pre-famine levels.

Prior to the 1990s, chemical fungicides were available in the United States and effectively held the disease at bay. But new strains of the pathogen have emerged, testing the limits of the technology and requiring American farmers to treat potato fields as many as a dozen times a season at a cost of up to $250 per acre. In warmer climates such as Mexico, fields may be treated as many as 25 times a year with the costly and toxic chemicals.

"We used to be able to get by, but the new (late-blight) strain just levels things in no time at all," says Helgeson.

The gene that protects potatoes from the fungus comes from a plant that scientists believe co-evolved in Mexico alongside the late-blight pathogen. It was discovered, ironically, as a result of the emergence of a new strain of P. infestans that swept through the United States in 1994. At UW-Madison’s Hancock Agricultural Research Station, the only plants to survive were the wild Mexican species and its progeny in Helgeson’s test plots.

Subsequent to the 1994 outbreak, which required the development of new fungicides for agriculture, Helgeson and his colleagues began the hunt for the genes that conferred resistance on the wild Mexican cousin of the domesticated tubers familiar to consumers.

In 2000, Helgeson’s lab reported narrowing the search to one of the 12 chromosomes of the wild plant. Now, with the gene identified, cloned and successfully tested in engineered varieties in the laboratory, at hand is a new technology that could save farmers hundreds of millions of dollars and benefit the environment by eliminating the application of thousands of tons of toxic chemicals.

But despite the huge economic and environmental gains that could be realized, it is unclear if the technology will be widely utilized. Because of European fears of genetically modified crops, and the control exercised over growers by a few large buyers, there is currently no engineered potato in commercial production anywhere.

The use of conventional breeding techniques to move the newfound blight-resistance gene into the few dominant commercial varieties popular in the United States is all but impossible, according to Jiang.

"We can do it by conventional breeding, but we can’t move it into the standard cultivated varieties without losing them," he says. "It is almost impossible to create another Burbank variety, for example, through conventional breeding. Your odds of getting the one gene in would be like winning the lottery."

Still, the Wisconsin group, plans to develop engineered varieties for the garden. The hope, they say, is to develop the technology that will gradually win consumer acceptance and, perhaps someday, go where no GMO has gone before.

The lead authors of the PNAS paper published today are Junqi Song of the UW-Madison department of horticulture and James M. Bradeen of the UW-Madison department of plant pathology and the U.S. Department of Agriculture’s Agricultural Research Service. Other co-authors include S. Kristine Naess and Geraldine T. Haberlach of the UW-Madison department of plant pathology and the U.S. Department of Agriculture’s Agricultural Research Service, John A. Raasch and Sandra Austin-Phillips of the UW-Madison Biotechnology Center, Susan M. Wielgus of the UW-Madison department of horticulture, Jia Liu and C. Robin Buell of the Institute for Genomic Research in Rockville, Md., and Hanhui Kuang of the department of vegetable crops at the University of California at Davis.


Terry Devitt 608-262-8282, trdevitt@facstaff.wisc.edu

CONTACT: Jiming Jiang 608-262-1878, jjiang1@wisc.edu; John Helgeson 608-262-0649, jph@plantpath.wisc.edu

Jiming Jiang | EurekAlert!
Further information:
http://www.wisc.edu/

More articles from Agricultural and Forestry Science:

nachricht New gene for atrazine resistance identified in waterhemp
24.02.2017 | University of Illinois College of Agricultural, Consumer and Environmental Sciences

nachricht Researchers discover a new link to fight billion-dollar threat to soybean production
14.02.2017 | University of Missouri-Columbia

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: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>