Safer Antifungals

Fungal diseases destroy more than 20% of the world’s five major crops each year, enough food to feed around 1 billion people. The losses cost the global economy more than $200 billion annually, hitting livelihoods and economies that depend on crops.

Farmers rely on fungicides to protect crops, but fungi can rapidly develop resistance to them, while some treatments can harm humans, pollinators and aquatic life. Replacing them is slow and costly: developing a new fungicide can take more than 12 years and cost over $300 million. Agricultural use can also encourage resistance in fungi that infect people, making some infections harder to treat.

Bdelloid rotifers offer an entirely new place to look for antifungals. These microscopic animals found in soil, moss and freshwater all over the world are remarkable survivors. They reproduce without males and can withstand extreme conditions, including complete desiccation and levels of radiation that are deadly to most animal life. Stranger still, over millions of years they have acquired thousands of genes from microbes and other organisms, including genes they appear to use in their own defence against fungal attack. Advances in genomics, synthetic biology and chemical analysis now make it possible to unlock this evolutionary innovation by identifying candidate antifungal pathways, reconstructing them in laboratory systems and characterising the natural products they produce.

This unusual evolutionary history could give scientists an advantage. Searches for natural antifungals have traditionally focused on compounds made by fungi and bacteria. But because bdelloid rotifers are animals, scientists think their antifungal defences may have evolved in ways that allow them to fight fungi without harming the animals themselves. If so, they could provide a largely unexplored source of compounds with a head start on one of the biggest challenges in developing new fungicides: finding treatments that kill fungi without also harming animals.

The Oxford Martin Programme on Safer Antifungals takes an unprecedented approach to antifungal discovery: looking to the natural defences of a microscopic animal for new ways to protect crops. An interdisciplinary team of researchers will produce and study promising compounds from these tiny animals, test whether they work against fungal diseases affecting crops and people, and investigate whether they harm plants or animals.

Rather than developing a single new fungicide, the programme aims to establish whether these microscopic animals could provide a repeatable source of safer antifungals. If the compounds prove effective and less harmful to animals, this unconventional approach could open a new route to developing crop treatments as resistance to existing fungicides grows.