Ustilago maydis, also known as Corn Smut, is a fungus which infects corn. The fungal infection usually occurs in the plant's ovaries, replacing the corn kernels with enlarged, distorted "galls" which then produce infective spores that are carried away by wind or rain. Like any good parasite, Ustilago feeds off its host, resulting in decreased yield in the infected crop. From an evolutionary biology view point, it is interesting to note that functionally, Ustilago acts rather like a parasitic castrator which reduces or eliminate the host's reproductive capacity, a strategy that has independently evolved in many parasite lineages. Whereas corn smut is considered as a blight on corn in Europe and North Armerica, in Mexico it is considered as a delicacy. Known as huitlacoche, this 'blight' fetch a higher price on the Mexican market than the corn itself. Its taste has been described as being similar to that of truffle - which is perhaps not too surprising as they are both are fungi that grow in association with a plant host. In addition to being a culinary treat, Ustilago maydis is also a useful lab model organism, used in research into plant diseases, as well as other research into cell and molecular biology.
Contributed by Tommy Leung.