While our life is spent above ground level, myriads of other creatures spend theirs below it. There are those, too, who share their time between both worlds - like moles, ants and trees for example. Soil offers protection but it is also a great source for food. Plants and fungi are perhaps among the organisms which make the best out of this state of affairs as they forage underground for essential nutrients while, above, leaves suck in sunlight for energy and mushrooms ripen to spread spores. Seeking sustenance underground requires a system that can rummage through earth, like roots in plants or rhizomorphs in fungi. In the recent years, there has been much talk about tree roots which are able to form intricate networks underground. The same goes for the mycelia of fungi. One particular fungus, Armillaria gallica, created a buzz in the 1990s when scientists announced that they had found a colony whose rhizomorphs seemingly stretched over tens of acres. However, as rhizomorphs grow, they also spend a lot of time fending off microbes that also want to prosper. Consequently, fungi yield numerous antimicrobial products, among them: melleolides, whose synthesis depends on an enzyme known as protoilludane synthase, or PRO1. Read more
