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

    US Internet Giants, EU Reach Deal to Combat Online Hate Speech

    Facebook, Twitter, Google and Microsoft commit to ‘quickly and efficiently’ act to clamp down on use of social media to incite violence, terror

    Video Tunisia’s Ennahda Party Begins a New Political Chapter

    Party now moves to separate its political and religious activities; change described by party members as pragmatic response to political and economic challenges facing Tunisia today

    Virtual Reality Fine-tuned at Asia Tech Show

    Microchip designers hope to improve resolution for users of systems that can turn your bedroom into the ocean floor

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Tech Startups Showcase Wares at Amsterdam Conferencei
    X
    Serginho Roosblad
    May 30, 2016 5:11 PM
    More than 20,000 tech enthusiasts, entrepreneurs and lovers of digital technology came together in Amsterdam recently at the Next Web Conference to discuss the latest developments in digital technology, look to the future and, of course, to connect. In recent years, there has been an explosion of so-called startup businesses that have created devices and applications that have changed the way we live; but, as Serginho Roosblad reports for VOA, there are pitfalls for such startups as well.
    Video

    Video Tech Startups Showcase Wares at Amsterdam Conference

    More than 20,000 tech enthusiasts, entrepreneurs and lovers of digital technology came together in Amsterdam recently at the Next Web Conference to discuss the latest developments in digital technology, look to the future and, of course, to connect. In recent years, there has been an explosion of so-called startup businesses that have created devices and applications that have changed the way we live; but, as Serginho Roosblad reports for VOA, there are pitfalls for such startups as well.
    Video

    Video US Military's Fallen Honored With Flags

    Memorial Day is a long weekend for most Americans. For some, it is the unofficial start of summer -- local swimming pools open and outdoor grilling season begins. But Memorial Day remains true to its origins -- a day to remember the U.S. military's fallen.
    Video

    Video Rolling Thunder Rolls Into Washington

    The Rolling Thunder caravan of motorcycles rolled into Washington Sunday, to support the U.S. military on the country's Memorial Day weekend
    Video

    Video A New Reading Program Pairs Kids with Dogs

    Dogs, it is said, are man's best friend. What some researchers have discovered is that they can also be a friend to a struggling reader. A group called Intermountain Therapy Animals trains dogs to help all kinds of kids with reading problems — from those with special needs to those for whom English is a second language. Faiza Elmasry has more on the New York chapter of R.E.A.D., or Reading Education Assistance Dogs, in this piece narrated by Faith Lapidus.
    Video

    Video Fan Base Grows for Fictional Wyoming Sheriff Longmire

    Around the world, the most enduring symbol of the U.S. is that of the cowboy. A very small percentage of Americans live in Western rural areas, and fewer still are cowboys. But the fascination with the American West is kept alive by such cultural offerings as “Longmire,” a series of books and TV episodes about a fictional Wyoming sheriff. VOA’s Greg Flakus recently spoke with Longmire’s creator, Craig Johnson, and filed this report from Houston.
    Video

    Video Chinese-Americans Heart Trump, Bucking National Trend

    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Reactions to Trump's Success Polarized Abroad

    What seemed impossible less than a year ago is now almost a certainty. New York real estate mogul Donald Trump has won the number of delegates needed to secure the Republican presidential nomination. The prospect has sparked as much controversy abroad as it has in the United States. Zlatica Hoke has more.
    Video

    Video Drawings by Children in Hiroshima Show Hope and Peace

    On Friday, President Barack Obama will visit Hiroshima, Japan, the first American president to do so while in office. In August 1945, the United States dropped an atomic bomb on the city to force Japan's surrender in World War II. Although their city lay in ruins, some Hiroshima schoolchildren drew pictures of hope and peace. The former students and their drawings are now part of a documentary called “Pictures from a Hiroshima Schoolyard.” VOA's Deborah Block has the story.
    Video

    Video Vietnamese Rapper Performs for Obama

    A prominent young Vietnamese artist told President Obama said she faced roadblocks as a woman rapper, and asked the president about government support for the arts. He asked her to rap, and he even offered to provide a base beat for her. Watch what happened.
    Video

    Video Roots Run Deep for Tunisia's Dwindling Jewish Community

    This week, hundreds of Jewish pilgrims are defying terrorist threats to celebrate an ancient religious festival on the Tunisian island of Djerba. The festivities cast a spotlight on North Africa's once-vibrant Jewish population that has all but died out in recent decades. Despite rising threats of militant Islam and the country's battered economy, one of the Arab world's last Jewish communities is staying put and nurturing a new generation. VOA’s Lisa Bryant reports.

    Special Report

    Adrift The Invisible African Diaspora