Growing fungal attacks on the world's most important agricultural crops threaten the planet's future food supply, scientists have said, warning that failing to combat fungal pathogens could lead to a "global health catastrophe."

Fungi are already by far the biggest destroyers of crops. They are highly hardy, travel long distances with the wind, and can feed on large fields of a single crop. They are also extremely adaptable and many have developed resistance to common fungicides.

According to the researchers, the impact of fungal diseases is expected to worsen as the climate crisis results in rising temperatures and causes fungal infections to constantly move toward the poles. Since the 1990s, fungal pathogens have been moving to higher latitudes at a rate of about 7 km per year. Wheat stem rust infections, typically found in the tropics, have already been reported in England and Ireland.

Warmer temperatures also drive the emergence of new variants of the fungal pathogens, while more extreme storms can spread their spores farther away, scientists say.

Professor Sarah Gurr of the University of Exeter in the UK, a co-author of the report, told the newspaper that the fungi had recently come to public attention through the hit TV show The Last of Us, in which fungi infect human brains. "While this storyline is science fiction, we are warning that we could see a global health catastrophe caused by the rapid global spread of yeast infections. The looming threat here is not about zombies, but about global hunger."

The scientists said there is also a risk that global warming will increase the fungi's tolerance to heat, increasing the possibility that they will jump on hosts to infect warm-blooded animals and humans.

"As our global population is projected to increase, humanity is facing unprecedented challenges to food production," said Professor Eva Stukenbrock of the University of Kiel in Germany, a co-author of the study. "We are already seeing massive crop losses due to fungal infections, which could sustain millions of people each year. This worrying trend can only get worse with global warming."

The warning, published in a paper in the scientific journal Nature, said growers have already lost between 10 percent and 23 percent of their crops to fungal diseases. In the five most important crops — rice, wheat, corn, soybeans and potatoes — infections cause annual losses that could feed hundreds of millions of people. Fungi are among the top six on a recent list of pests and pathogens with the greatest impact.

The fungi are incredibly hardy, the researchers say, remaining viable in the soil for up to 40 years, and their airborne spores can travel between continents. "After the tornadoes in America, you can see that the spores got sucked in and left for long-distance travel," Gurr said.

Fungicides are widely used, but pathogens are well-equipped to rapidly develop resistance to treatments that target only a single cellular process. Existing fungicides and conventional breeding for disease resistance are no longer sufficient, according to the researchers.

One solution is to plant seed mixtures that carry a variety of genes resistant to fungal infections, rather than monocultures of a single strain. By 2022, about a quarter of the wheat in Denmark was grown this way. The technology could also help, scientists say, with drones and artificial intelligence, enabling early detection and control of outbreaks.

New pesticides are being developed, with a team from the University of Exeter recently discovering compounds that can lead to chemicals that target various biological processes within fungi, making resistance much harder to develop. The approach has already proven useful against fungi that infect wheat, rice, corn and bananas.

The researchers said research into fungal pathogens was seriously underfunded, comparing the £550 million allocated to Covid-19 research by the UK Research and Innovation Council from 2020 to 2022 with the £24 million for fungal culture research over the same period. "If we don't have enough to eat, malnutrition will kill us before we catch something like Covid-19," Gurr said.  "But our [research area] is absolutely poor compared to every medical disease you can imagine."

Source: Um só Planeta