News / Science & Technology

    Genes Found to Fight Wheat Disease

    Varying stem rust epidemics on wheat stems (Photo: Evans Lagudah & Zakkie Pretorius)
    Varying stem rust epidemics on wheat stems (Photo: Evans Lagudah & Zakkie Pretorius)
    Scientists have isolated two genes that protect wheat plants from a disease that threatens the crop worldwide.

    In two articles in the journal Science, researchers describe a pair of genes that confer resistance to a new, virulent form of a fungal disease called stem rust.

    At its worst, stem rust can wipe out nearly an entire wheat field. After a 1953 outbreak destroyed 40 percent of the U.S. spring wheat harvest, scientists bred new varieties with resistance to the disease.

    That solved the problem for several decades.

    Out of Africa

    “But then, just in 1999, a new race evolved in Africa," says Kansas State University plant disease expert Eduard Akhunov. "And they found that it overcomes all these resistance genes.”

    First found in Uganda, this new "race" - a strain called Ug99 - has spread from South Africa to Iran.

    But experts are worried the fungus won’t stop there. Nearly all of the world’s commercial wheat varieties are susceptible to it.

    A global effort is under way to create new, Ug99-proof varieties.

    Akhunov is co-author of one article. He says both genes described in the new articles come from wheat’s wild relatives.

    New alarm system

    “Our gene is some kind of surveillance molecule that will try to sense if [the] pathogen is invading or not,” Akhunov says.

    He says wheat plants don’t sense that Ug99 is invading because the fungal proteins that used to set off alarms have mutated.

    The newly described genes restore the wheat plant’s ability to recognize the invading fungus, says plant biologist Jan Dvorak at the University of Califoria at Davis, co-author of the other new article.

    “The gene for resistance is a gene which gives the wheat plant a sensor again," says Dvorak. "It says, ‘Ah, we missed this guy.’ And the wheat plant suddenly is able to see again.”

    Breeding better wheat

    Eduard Akhunov says researchers could use genetic engineering to quickly put both genes into wheat plants at the same time. But he says now may not be the time because many people don’t trust gene-splicing technology.    

    “Maybe in the future," Akhunov says. "Because until the public is ready for that, I don’t think there is a way of using that approach.”

    Others say genetic engineering may not save much time because of advances in conventional breeding. When conventional breeders mate two plants, they use genetic markers to find offspring with the genes they want.

    “Now you have the perfect markers," says Jose Costa, head of grain crop research at the U.S. Department of Agriculture. "It makes things a lot easier and more targeted.”

    Wheat varieties resistant to Ug99 have been released in several South Asian countries. More are on the way. But experts warn that diseases will continue to evolve, and fighting them is a never-ending battle.

    Steve Baragona

    Steve Baragona is an award-winning multimedia journalist covering science, environment and health.

    He spent eight years in molecular biology and infectious disease research before deciding that writing about science was more fun than doing it. He graduated from the University of North Carolina at Chapel Hill with a master’s degree in journalism in 2002.

    You May Like

    Beijing Warns Critics Over South China Sea Dispute

    Official warns critics that the more they challenge China's position regarding disputed territories in one of world’s busiest waterways, the more it will push back

    Will New Russian Force Be 'Putin’s Personal Army'?

    With broad powers to control riots, suppress dissent, National Guard may be aimed at sending a message to West as much as keeping peace at home

    Foreign Media in Pyongyang Barred From North Korean Party Congress

    Hundreds of international journalists invited to cover historic party meeting barred from entering actual event

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Image Recognition Market Seen Doubling by 2020i
    X
    Ramon Taylor
    May 05, 2016 10:05 PM
    From auto tagging on Facebook to self-driving cars, image recognition technology as it exists today is still in its beginning phases, experts say — and will soon change the way users and corporations interact with the physical world. VOA's Ramon Taylor reports.
    Video

    Video Image Recognition Market Seen Doubling by 2020

    From auto tagging on Facebook to self-driving cars, image recognition technology as it exists today is still in its beginning phases, experts say — and will soon change the way users and corporations interact with the physical world. VOA's Ramon Taylor reports.
    Video

    Video Child Labor in Afghanistan Remains a Problem

    With war still raging in Afghanistan, the country also faces the problem of child labor as families put their school-age children to work to help make ends meet. But, thanks to VOA's Afghan Service, two families whose children had been working in a brick-making factory - to earn their livings and pay off family debts - now have a new lease on life. Zabihullah Ghazi reports.
    Video

    Video Kurdish Troops Recount Firefight Which Killed US Navy SEAL

    A U.S. Navy SEAL killed Tuesday, when Islamic State fighters punched through Kurdish lines in northern Iraq, was part of a quick reaction force sent to extract other U.S. troops trapped by the surprise offensive. VOA's Kawa Omar spoke with Kurdish troops in the town of Telskuf -- the scene of what U.S. officials called a "dynamic firefight."
    Video

    Video British Lawmakers Warn EU Exit Talks Could Last A Decade

    Leaving the European Union would mean difficult negotiations that could take years to complete, according to a bipartisan group of British lawmakers. While the group did not recommend a vote either way, the lawmakers noted trade deals between the EU and non-EU states take between four and nine years on average. Henry Ridgwell reports on the mounting debate over whether Britain should stay or exit the EU as the June vote approaches.
    Video

    Video NASA Astronauts Train for Commercial Space Flights

    Since the last Shuttle flight in 2011, the United States has been relying on Russian rockets to launch fresh crews to the International Space Station. But that may change in the next few years. NASA and several private space companies are developing advanced capsules capable of taking humans into low orbit and beyond. As VOA's George Putic reports, astronauts are already training for commercial spacecraft in flight simulators.
    Video

    Video US Worried Political Chaos in Iraq Will Hurt IS Fight

    The White House is expressing concern about rising political chaos in Iraq and the impact it could have on the fight against the Islamic State. The U.S. says Iraq needs a stable, central government to help push back the group. But some say Baghdad may not have a unified government any time soon. VOA's White House correspondent Mary Alice Salinas reports.
    Video

    Video Press Freedom in Myanmar Fragile, Limited

    As Myanmar begins a new era with a democratically elected government, many issues of the past confront the new leadership. Among them is press freedom in a country where journalists have been routinely harassed or jailed.
    Video

    Video Taliban Threats Force Messi Fan to Leave Afghanistan

    A young Afghan boy, who recently received autographed shirts and a football from his soccer hero Lionel Messi, has fled his country due to safety concerns. He and his family are now taking refuge in neighboring Pakistan. VOA's Ayaz Gul reports from Islamabad.
    Video

    Video Major Rubbish Burning Experiment Captures Destructive Greenhouse Gases

    The world’s first test to capture environmentally harmful carbon dioxide gases from the fumes of burning rubbish took place recently in Oslo, Norway. The successful experiment at the city's main incinerator plant, showcased a method for capturing most of the carbon dioxide. VOA’s Deborah Block has more.
    Video

    Video EU Visa Block Threatens To Derail EU-Turkey Migrant Deal

    Turkish citizens could soon benefit from visa-free travel to Europe as part of the recent deal between the EU and Ankara to stem the flow of refugees. In return, Turkey has pledged to keep the migrants on Turkish soil and crack down on those who are smuggling them. Brussels is set to publish its latest progress report Wednesday — but as Henry Ridgwell reports from London, many EU lawmakers are threatening to veto the deal over human rights concerns.
    Video

    Video Tensions Rising Ahead of South China Sea Ruling

    As the Philippines awaits an international arbitration ruling on a challenge to China's claims to nearly all of the South China Sea, it is already becoming clear that regardless of which way the decision goes, the dispute is intensifying. VOA’s Bill Ide has more from Beijing.
    Video

    Video Painting Captures President Lincoln Assassination Aftermath

    A newly restored painting captures the moments following President Abraham Lincoln’s assassination in 1865. It was recently unveiled at Ford’s Theatre in Washington, where America’s 16th president was shot. It is the only known painting by an eyewitness that captures the horror of that fateful night. VOA’s Julie Taboh tells us more about the painting and what it took to restore it to its original condition.

    Special Report

    Adrift The Invisible African Diaspora