The smuts are multicellular

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

characterized by their large numbers of teliospores. The smuts get their name from a Germanic word for dirt because of their dark, thick-walled, and dust-like teliospores. They are mostly

Ustilaginomycetes Ustilaginomycetes is the class of true smut fungi. They are plant parasites with about 1400 recognised species in 70 genera. They have a simple septum with a septal pore cap, this is different from Agaricomycotina which has a dolipore septum with ...

(phylum Basidiomycota) and can cause

plant disease Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomy ...

. The smuts are grouped with the other

basidiomycetes Basidiomycota () is one of two large divisions that, together with the Ascomycota, constitute the subkingdom Dikarya (often referred to as the "higher fungi") within the kingdom Fungi. Members are known as basidiomycetes. More specifically, Ba ...

because of their commonalities concerning sexual reproduction. Smuts are cereal and crop

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

s that most notably affect members of the grass family ( Poaceae) and sedges ( Cyperaceae). Economically important hosts include

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley p ...

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

oats The oat (''Avena sativa''), sometimes called the common oat, is a species of cereal grain grown for its seed, which is known by the same name (usually in the plural, unlike other cereals and pseudocereals). While oats are suitable for human co ...

, sugarcane, and forage grasses. They eventually hijack the plants' reproductive systems, forming galls which darken and burst, releasing fungal

teliospore Teliospore (sometimes called teleutospore) is the thick-walled resting spore of some fungi ( rusts and smuts), from which the basidium arises. Development They develop in '' telia'' (sing. ''telium'' or ''teliosorus''). The telial host is the p ...

s which infect other plants nearby. Before infection can occur, the smuts need to undergo a successful mating to form dikaryotic hyphae (two haploid cells fuse to form a

dikaryon The dikaryon is a nuclear feature which is unique to certain fungi. (The green alga ''Derbesia'' had been long considered an exception, until the heterokaryotic hypothesis was challenged by later studies.) Compatible cell-types can fuse cytoplasms ( ...

Wild rice smut

'' Ustilago esculenta'' is a species of fungus in the Ustilaginaceae, a family of smut fungi. It is in the same genus as the fungi that cause corn smut, loose smut of barley, false loose smut, covered smut of barley, loose smut of oats, and other grass diseases. This species is pathogenic as well, attacking Manchurian wild rice (''

Zizania latifolia ''Zizania latifolia'', known as Manchurian wild rice (), is the only member of the wild rice genus '' Zizania'' native to Asia. It is used as a food plant. Both the stem and grain are edible. Gathered in the wild, Manchurian wild rice was an impo ...

''), also known as Manchurian ricegrass, Asian wild rice, and wateroat. This grass is its only known host. When the fungus invades the host plant it causes it to

hypertrophy Hypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It is distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number.Updated by Linda J. ...

, its cells increasing in size and number. The fungus destroys the flowering structures of the plant, so it does not make seed. The crop is propagated asexually, by rhizome. New sprouts are infected by spores in the environment, which is generally a paddy. The fungus can also be transmitted directly in the rhizome. Manchurian wild rice is grown as an agricultural crop across Asia. The success of the crop depends on the smut fungus ''Ustilago esculenta''. The grass is not grown for its grain, as are other wild rice species, but for the stems, which swell into juicy galls when infected with the smut. The galled stems are harvested as a vegetable known as Simp: 茭笋; Trad: 茭筍 (

Pinyin Hanyu Pinyin (), often shortened to just pinyin, is the official romanization system for Standard Chinese, Standard Mandarin Chinese in China, and to some extent, in Singapore and Malaysia. It is often used to teach Mandarin, normally writte ...

: jiāo sǔn) or 茭白 (Pinyin: jiāo bāi) in China. Its Japanese name is makomotake. It is popular for its tender flavor and texture. Its taste resembles fresh bamboo shoots. It can be eaten raw or cooked. It stays crisp when

stir-fried Stir frying () is a cooking technique in which ingredients are fried in a small amount of very hot oil while being stirred or tossed in a wok. The technique originated in China and in recent centuries has spread into other parts of Asia and t ...

Sugarcane smut

Sugarcane smut Sugarcane smut is a fungal disease of sugarcane caused by the fungus ''Sporisorium scitamineum''. The disease is known as culmicolous, which describes the outgrowth of fungus of the stalk on the cane. It attacks several sugarcane species and has ...

is caused by the fungus ''

Sporisorium scitamineum Sugarcane smut is a fungal disease of sugarcane caused by the fungus ''Sporisorium scitamineum''. The disease is known as culmicolous, which describes the outgrowth of fungus of the stalk on the cane. It attacks several sugarcane species and has ...

''; smut was previously known as ''

Ustilago scitaminea ''Ustilago'' is a genus of approximately 200 smut fungi parasitic on grasses. Uses ''Ustilago maydis'' is eaten as a traditional Mexican food in many parts of the country, and is even available canned. Farmers have even been known to spread th ...

''. The smut 'whip' is a curved black structure which emerges from the leaf whorl, and which aids in the spreading of the disease. Sugarcane smut causes significant losses to the economic value of a sugarcane crop. Sugarcane smut has recently been found in the eastern seaboard areas of Australia, one of the world's highest-yielding sugar areas. For the sugarcane crop to be infected by the disease, large spore concentrations are needed. The fungi uses its ''smut-whip'' to ensure that the disease is spread to other plants, which usually occurs over a time period of three months. As the inoculum is spread, the younger sugarcane buds just coming out of the soil will be the most susceptible. Because water is necessary for spore germination, irrigation has been shown to be a factor in spreading the disease. Therefore, special precautions need to be taken during irrigation to prevent spreading of the smut. Another way to prevent the disease from occurring in the sugarcane is to use fungicide. This can be done by either pre-plant soaking or post-plant spraying with the specific fungicide. Pre-plant soaking has been proven to give the best results in preventing the disease, but post-plant spraying is a practical option for large sugarcane cultivations.

Corn smut

Corn smut Corn smut is a plant disease caused by the pathogenic fungus ''Ustilago maydis'' that causes smut on maize and teosinte. The fungus forms galls on all above-ground parts of corn species. It is edible, and is known in Mexico as the delicacy ''h ...

(''Ustilago maydis'') infects

and is a delicacy in

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, where it was historically enjoyed by the Aztecs. It grows in the ears of the corn crops and converts the kernels into black, powdery fungal tissues. The smut is sold in the markets in Mexico while other parts of the world (including the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

) continue to reject it as an ingredient for food dishes. Corn smut is currently called ''huitlacoche'' by some Mexicans, and the Aztecs formerly called it ''cuitlacoche''. Investigators have recently found that the amount of protein in corn smut is greater than that of the corn, and also greater than that of oats and clover hay.McMeekin, D. 1999. Different perceptions of the Corn Smut fungus. Mycologist. 13 (4). 180-183. ''Huitlacoche'' is used for some of the several recipes including soups, stews, steak sauces and crepes.

References

External links

''Smut Fungi'' from Deacon, J: "Fungal Biology", Blackwell Publishing, 2005
{{DEFAULTSORT:Smut (Fungus) Fungus common names Fungal plant pathogens and diseases Basidiomycota

Wild rice smut

Sugarcane smut

Corn smut

See also

References

External links