Scientists have warned of the ‘devastating’ impact that fungal diseases in crops will have on the global food supply unless agencies around the world come together to find new ways to fight the infection

Worldwide, growers lose between 10 and 23 percent of their crops each year to fungal infections, despite the widespread use of antifungals. an additional 10-20% is lost after harvest[GS1] . In a comment in Natureacademics predict these numbers will get worse as global warming means fungal infections are steadily moving poleward[GS2] [GS3] [GS4] [VL5] , which means that more countries are likely to experience a higher prevalence of crop-damaging fungal infections*. Growers have already reported wheat stem rust infections – which normally occur in the tropics – in Ireland and England. Experts also warn that tolerance to higher temperatures in fungi could increase the likelihood of opportunistic soil-dwelling pathogens for hop hosts and infecting animals or humans.

Professor Sarah Gurr, who holds the chair of food safety at the University of Exeter, is a co-author of the report. She said mushrooms have recently gained attention through the hit TV show The Last of Us, in which mushrooms invade the human brain. She said: “Although the scenario 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. The looming threat here is not about ‘zombies,’ but about global starvation.”

Around the world, food security is expected to face unprecedented challenges, as increasing population means increased demand. In the five most important calorie crops of rice, wheat, maize (maize), soybeans and potatoes, infections lead to losses that are equivalent to enough food to supply some 600 million to 4 billion people 2,000 calories a day for a year.

Commentary co-author Eva Stukenbrock, professor and head of the environmental genomics group at Christian-Albrechts-University in Kiel, Germany, and fellow at the Canadian Institute for Advanced Research (CIFAR), said: “So that our world population is expected to grow, humanity faces unprecedented challenges in food production. We are already seeing massive crop losses due to fungal infections, which could sustain millions of people every year. This worrying trend can only get worse as global warming makes fungal infections more prevalent in European crops, and as they continue to develop resistance to antifungals. This will be catastrophic for developing countries and will also have a major impact in the Western world.

The comment highlights a “perfect storm” that causes fungal infections to spread rapidly. Among the factors is that the fungi are incredibly hardy, remaining viable in the soil for up to 40 years, with airborne spores that can travel between continents. Moreover, they are extremely adaptable, with “phenomenal” genetic diversity between and among species. Modern agricultural practices involve large areas of genetically uniform crops, which provide the ideal feeding and breeding grounds for such a prolific and rapidly changing group of organisms. They are also well equipped to evolve beyond traditional means of controlling their spread. The increasingly widespread use of antifungal treatments targeting a single fungal cellular process means that fungi can develop resistance to these fungicides, so that they are no longer effective. This forces farmers to use ever-higher concentrations of fungicides in an effort to control infection, which can accelerate the rate of resistance development.

However, there are reasons for hope. In 2020, a team from the University of Exeter [GS6] discovered a new chemistry that could pave the way for a new type of antifungal that targets several different mechanisms, meaning it’s much harder for fungi to develop resistance. The Exeter group found the antifungal to be useful against a range of fungal diseases – tritici septoria leaf spot on wheat, rice borer, corn smut[GS7] ** and against the fungus responsible for banana Panama disease***.

Farming practices may also hold the key to change, after a study in Denmark showed promise by planting seed mixes that carry a range of genes resistant to fungal infections. Technology can also prove crucial, with AI, citizen science and remote sensing tools such as drones enabling early detection and control of outbreaks.

Overall, the authors say protecting the world’s crops from fungal diseases will require a much more unified approach, bringing together farmers, the agricultural industry, plant breeders, biologists, governments, policymakers and donors. of funds.

Professor Sarah Gurr concluded: “Fungal infections threaten some of our most important crops, from potatoes to cereals and bananas. We are already seeing massive casualties, and this threatens to become a global catastrophe given population growth. Recently we have seen the world unite in the face of the threat to human health posed by covid We now urgently need a globally united approach to fight fungal infections, with more investment, from governments, philanthropic organizations and private companies, to harness the seeds of hope and stop this development in a global catastrophe that will see people starve.”

The commentary is titled “Addressing the growing emergency of fungal diseases in crops[VL8] “, and is published in Nature.

* Bebber, DP, Ramotowski, MAT & Gurr, SJ Nature Clim. Change 3, 985-988 (2013).

** Steinberg, G. et al. Nature Common. 11, 1608 (2020)

***Cannon, S. et al. PLoS Pathog. 18, e1010860 (2022)