Mushrooms aren’t just a delicious pizza topping. They could help us colonise other planets, tackle plastic pollution and even rescue beleaguered bees.
Did you know there are 10 times more species of fungi than plants? That with every woodland footfall we are stepping on kilometres of fungal threads? Or that with every breath, we breathe in up to 10 fungal spores? If you don’t, you are not alone.
Most of us are ignorant about the fungi kingdom. Perhaps it’s because, for many people, these incredible organisms have the ‘ick factor’. A large number of fungi are decomposers: they get their food by harvesting nutrients from dead and dying organisms, and we often associate anything to do with decay as rather creepy. What’s more, toadstools have been credited with all kinds of mischief, from deflowering virgins (not possible) to melting your liver in a matter of days (very possible, if you eat certain species).
Nor has it helped that fungi are primarily microscopic. When we see mushrooms growing in the wild, we are only seeing the fruiting body of the organism, which produces spores for reproduction. The rest of it is a mass of fungal threads called ‘hyphae’, which are hidden from sight and forage for nutrients inside wood or soil. It wasn’t until we had powerful microscopes to see fungi clearly that we were able to understand their metabolism and finally get a sense of how huge the realm of fungi really is.
Fungi are present in the microbiomes of all living things and even exist in the atmosphere. But they mainly reside in soil and plants, where they are integral to the wellbeing of forest and field ecosystems, to the recycling of nutrients, and to the sequestration of carbon.
Fungi are responsible for countless duties in nature, and the molecules they have evolved to fulfil those duties represent a range of opportunities that may help us solve some of the world’s most vexing problems. This is an exciting time, when bioprospectors, entrepreneurs and ecologists are all rethinking what the future could look like. And what they are seeing is that the future is fungal.
How fungi could save agriculture in a warming world
You probably don’t know it, but when you look at a plant, you are looking at fungi, too. That’s because most, if not all, terrestrial plants host thread-like fungi between their cells. The fungi feast on sugars the plant makes, and in exchange, they help plants tolerate stressful environmental conditions like salt inundation, drought and high temperatures.
When a plant is exposed to drought it suffers from oxidative stress – an imbalance of free radicals and antioxidants – which can hurt its cells. But unlike you and me, plants don’t produce helpful chemicals to counter the effects of that stress; instead, it’s the endophytic fungi living between the cells of the plants that do.
These impossibly thin fungal threads emit an arsenal of compounds that calm oxidative stress in plants, and also participate in the chemistry that makes plants use water efficiently. This helps plants with a drought problem, but also those suffering from extreme heat or salt exposure.
Researchers have found that stress-reducing endophytic fungi can be transferred from their host plants to crop plants in order to help them survive in a warming world. For example, the fungus that allows panic grass to grow in soil temperatures of up to 65°C also allows tomatoes to grow and fruit in similarly hot conditions.
To the fungus, panic grass and tomatoes are the same thing, and the implications are enormous: in a rapidly warming world, endophytic fungi have the potential to protect our food supply.