Fungi pose a significant threat to crops around the world, scientists warn in a new commentary, with increasingly “devastating” effects on our food supply.
We tend to worry more about pathogens that directly affect humans, especially virus and bacteria. But although corn smut and stalk rust may not frighten us like Ebola Or E.colimaybe they should.
These fungi are already taking their toll, with growers around the world losing up to 23% of their crops each year to fungal infections. Mushrooms require an additional 10-20% after harvest, they add.
Due to their effects on five of the world’s most calorie-dense crops – rice, wheat, corn, soybeans and potatoes – fungi currently destroy enough food to provide 2,000 calories a day for a year to between 600 million and 4 billion people.
And the situation is getting worse thanks to a “perfect storm” of factors leaving swaths of farmland dangerously vulnerable to fungi, according to Sarah Gurr, a plant pathologist at the University of Exeter.
Even if they don’t turn us into zombies, like a fictional mushroom (or slime mold) made to humans in the HBO drama The last of us, these mushrooms are no less of a nightmare, warns Gurr. Moreover, they are real.
“Although the story is science fiction, we warn that we could see a global health catastrophe caused by the rapid global spread of fungal infections as they develop increasing resistance in a warming world,” said she declared. said. “The looming threat here is not zombies, but global starvation.”
Farmers have battled fungi for millennia, but not quite like this, write Gurr and co-author Eva Stukenbrock, environmental genomics at Christian-Albrechts-University Kiel.
Climate change is a key difference since the extra heat helps some mushrooms extend their ranges (among others disturbing adaptations), including species that threaten major food crops.
Humans have also invited this crisis in other ways, researchers to writesuch as establishing large monocultures of genetically similar crops, which are particularly susceptible to fungal outbreaks.
And while fungicides have helped growers fend off these outbreaks for the past few generations, fungi are finding ways to bypass even the most robust defenses, Gurr and Stukenbrock. explain.
Many fungicides work by targeting a single cellular process, which allows fungi to develop resistance – an opportunity fungi seem eager to seize.
As fungicides lose their effectiveness on newly resistant fungi, frustrated farmers sometimes react by using higher concentrations of the same fungicides, which can make matters worse.
With rising temperatures, the failure of pesticides, and large monocultures virtually defenseless against fungus, our crops are like sitting ducks.
And for more than 8 billion people now inhabit Earth — many of which are already food insecure, often due to other effects of climate change — now is not the best time for fungi to wipe out food sources, Stukenbrock notes.
“While our global population is set to soar, humanity faces unprecedented challenges in food production,” she said. said. “We are already seeing massive crop losses due to fungal infection, which could sustain millions of people every year.”
These losses are already a disaster that requires global attention, but the new commentary aims to highlight how serious the situation has become and how much worse it could get worse.
“This worrying trend can only get worse as global warming makes fungal infections more prevalent in European crops and they continue to develop resistance to antifungals,” Stukenbrock said. said. “It will be catastrophic for developing countries and will also have a major impact in the Western world.”
Since humans helped create this mess, at least we have the power to fix some of it, Gurr and Stukenbrock argue.
Besides the obvious but elusive goal of reducing climate change-causing emissions, which is already vitally important for other reasons, there could be a few ways to better protect our crops from fungi in the short term. .
Researchers at the University of Exeter have developed new techniques that could enable a new class of fungicides targeting multiple cellular mechanisms, Gurr and Stukenbrock notemaking it more difficult for fungi to develop resistance.
Research suggests that this type of antifungal can work against several major pathogens, they add, including corn smut, rice borer and the fungus responsible for Fusarium wilt of bananas.
Even without better fungicides, we could reduce the risk of fungal outbreaks simply by adopting better agricultural practices, Gurr and Stukenbrock suggestciting a project in Denmark that successfully controlled fungal infections by planting genetically diverse seed mixtures.
“Fungal infections threaten some of our most important crops, from potatoes to grains and bananas,” Gurr said. “We are already seeing massive casualties, and this threatens to become a global catastrophe in light of population growth.”
The comment was posted in Nature.