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 3-D model predicts best planting practices for farmers
26.06.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht Fighting a destructive crop disease with mathematics
21.06.2017 | University of Cambridge

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>