The fiery taste of chillies is a defence against a fungus

Food from countries all over the world owes a lot of its flavour to a fungus. The species in question isn't one of the many edible mushrooms used for cooking, the baker's yeast that gives rise to bread, or the moulds that spread through blue cheese. It's a little known species called Fusarium semitectum and its role has only just been discovered - it's the driving force behind the fiery heat of chillies.