ergot

(ûr`gət), disease of rye and other cereals caused by the fungus Claviceps purpurea. The cottony, matlike body, or mycelium, of the fungus develops in the ovaries of the host plant; it eventually turns into a hard pink or purple body, the sclerotium, or ergot, that resembles a grain of rye in shape. The sclerotium contains alkaloids (many of which are biologically active) that are toxic to humans and livestock. Ergot poisoning, or ergotism, epidemic in the Middle Ages, results from eating bread made of rye contaminated with ergot. Ergot poisoning is characterized by constriction of blood vessels, resulting in numbness and the development of gangrene in extremities; it may also affect the nervous system. Some of the alkaloids in ergot, e.g., ergotamine and ergonovine, are used as medicines; these alkaloids are chemical derivatives of lysergic acid, which is used in the synthesis of the hallucinogen LSDLSD
or lysergic acid diethylamide
, alkaloid synthesized from lysergic acid, which is found in the fungus ergot (Claviceps purpurea). It is a hallucinogenic drug that intensifies sense perceptions and produces hallucinations, mood changes, and changes in the
..... Click the link for more information. . Ergotamine alleviates migraine headaches. Ergonovine is used medicinally to stop hemorrhage and cause contraction of the uterus; during the 17th cent. midwives used ergot to stop postpartum uterine bleeding.

Ergot

(1) The parasitic fungus Claviceps purpurea of the class Ascomycetes of the group Pyrenomycetes.

(2) A disease of cereals caused by the fungus Clavicepspurpurea and characterized by the formation of violet sclerotia instead of grains in the spikes. The sclerotia, which represent a resting stage of the fungus, are 1–5 cm long and contain poisonous substances that may cause ergotism, a serious disease of humans and animals contracted by eating contaminated grain or grain products. In the past epidemics and epizooties of ergotism were common in many countries. As a result of advancements in agriculture, the incidence of ergot in cereal crops has decreased.

The causative agent of ergot, which affects more than 170 cultivated and wild cereals, most commonly attacks rye. Sclerotia form, as a rule, in the female sex organs (ovaries). The fungus reproduces by spores, which are distributed during flowering of the cereals by rain, wind, animals, and humans. The disease occurs in regions having a temperate or humid climate. Damage may be substantial: for example, if a spike contains more than 20 sclerotia, only about 20 percent of the nutrient matter entering the spike will be used in grain formation.

Control measures include removing sclerotia from the grains of rye and other cereals; uniform planting of winter and spring cereals to ensure uniform development, flowering, and ripening; inspecting plantations to identify healthy seed-growing plots; shallow plowing of stubble; deep autumn plowing; and selecting varieties with short and uniform periods of flowering.

Z. P. KACHALOVA

(3) Sclerotia of the fungus Claviceps purpurea. The sclerotia contain a large number of alkaloids (derivatives of lysergic acid), biogenic amines (histamine and tyramine), choline, acetylcholine, amino acids, and other substances. The ergot alkaloids are divided into three basic groups: ergotamine, ergometrine (ergobasine), and ergotoxine. Ergot alkaloids and their derivatives exert a complex action on the body (for example, on the uterus, sympathetic nervous system, and central nervous system). The characteristic feature of the alkaloids—mainly of ergometrine and ergotamine—is the ability to induce uterine contractions. The alkaloids are used to sedate the nervous system, lower the basal metabolism, and treat spasms of the blood vessels and hypertension. Ergotamine is effective against migraine.

Sclerotia of ergot are cultivated for medicinal purposes in rye plantings on special farms. The plants are infected during spike formation with the conidiospores of special strains of C. purpurea that produce sclerotia with high alkaloid content.

V. V. PARIN

REFERENCES

Pshedetskaia, L. I. Biologicheskie osobennosti sporyn’i na kul’turnykh i lugovykh zlakakh, kak material dlia obosnovaniia meropriiatiipo bor’bes nei.
Leningrad, 1953. (Dissertation.) Lekarstvennye rasteniia SSSR (kul’tiviruemye i dikorastushchie). Moscow, 1967.
Peresypkin, V. F. Sel’ skokhoziaistvennaia fitopatologiia. Moscow, 1969.

ergot

[′ər·gət] (mycology) The dark purple or black sclerotium of the fungus Claviceps purpurea. (organic chemistry) Any of the five optically isomeric pairs of alkaloids obtained from this fungus; only the levorotatory isomers are physiologically active.

ergot

the dried sclerotia of C. purpurea, used as the source of certain alkaloids used to treat haemorrhage, facilitate uterine contraction in childbirth, etc.

ergot

[er´got] the dried sclerotium of the fungus Claviceps purpurea, which attacks rye plants. Ergot alkaloids are used as oxytocics and in treatment of migraine. Consumption of excessive amounts of ergot can cause the toxicity known as ergotism.

er·got

(er'got), The resistant, overwintering stage of the parasitic ascomycetous fungus Claviceps purpurea, a pathogen of cereal rye that transforms the seed of rye into a compact spurlike mass of fungal pseudotissue (the sclerotium) containing five or more optically isomeric pairs of alkaloids. The levorotary isomers induce uterine contractions, control bleeding, and alleviate certain localized vascular disorders (migraine headaches).
See also: ergotism. Synonym(s): rye smut [O. Fr. argot, cock's spur]

ergot

(ûr′gət, -gŏt′)n.1. Any of several fungi of the genus Claviceps, especially C. purpurea, that infect various cereal plants and form compact black masses of branching filaments that replace the grains of the host plant. Humans and livestock can be poisoned by ingesting ergot-infected grains.2. The plant disease caused by such a fungus.3. The dried sclerotia of ergot, usually obtained from rye seed and used as a source of several medicinally important alkaloids and as the basic source of lysergic acid.

er·got′ic adj.

ergot

Herbal medicine
A fungus that infects rye, which is the primary source for ergonovine and ergotamine; its use in herbal medicine is confined to haemostasis and strengthening uterine contractions during childbirth.

er·got

(ĕr'got) The resistant, overwintering stage of the parasitic ascomycetous fungus Claviceps purpurea, a pathogen of cereal rye that transforms the seed of rye into a compact, spurlike mass of fungal pseudotissue (the sclerotium) containing five or more optically isomeric pairs of alkaloids. The levorotary isomers induce uterine contractions, control bleeding, and alleviate some localized vascular disorders (migraine headaches). [O. Fr. argot, cock's spur]

ergot

One of various fungi of the genus Claviceps , that can grow on rye and other cereal plants and cause the serious condition of ERGOTISM by virtue of its alpha-adrenoceptor stimulating action. Ergot is the source of various valuable drugs such as ERGOTAMINE and ERGOMETRINE. It is also the source of lysergic acid.

ergot

a disease caused by the ascomycete Claviceps purpurea in cereals and grasses.
a SCLEROTIUM forming in place of a grain in a diseased grain head. Ergots contain substances that are poisonous and are sometimes used medicinally.

er·got

(ĕr'got) Resistant, overwintering stage of the parasitic ascomycetous fungus Claviceps purpurea. [O. Fr. argot, cock's spur]

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Synonyms for ergot

noun a plant disease caused by the ergot fungus

Related Words

noun a fungus that infects various cereal plants forming compact black masses of branching filaments that replace many grains of the plant

Synonyms

Related Words