Ergot
262925
224973452
2008-07-11T07:11:38Z
Lightbot
7178666
Units/dates/other
{{Taxobox
| name = Ergot
| image = Koeh-185.jpg
| image_width = 250px
| image_caption = ''Claviceps purpurea''
| regnum = [[Fungus|Fungi]]
| divisio = [[Ascomycota]]
| classis = [[Euascomycetes]]
| ordo = [[Hypocreales]]
| familia = [[Clavicipitaceae]]
| genus = '''''Claviceps'''''
| subdivision_ranks = [[Species]]
| subdivision =
About 50, including:<br>
''Claviceps africanum''<br>
''Claviceps fusiformis''<br>
''Claviceps paspali''<br>
''Claviceps purpurea''<br>
}}
'''Ergot''' is the common name of a [[fungus]] in the genus ''Claviceps'' that is parasitic on certain grains and grasses. The fungus forms a [[sclerotium]] in winter, and this small structure is what is usually referred to as 'ergot', although referring to the members of the ''Claviceps'' genus as 'ergot' is also correct. There are about 50 known species of ''Claviceps'', most of them in the tropical regions. Economically important species are ''Claviceps purpurea'' (parasitic on [[Poaceae|grass]]es and cereals), ''C. fusiformis'' (on [[pearl millet]], buffel grass), ''C. paspali'' (on dallis grass), and ''C. africana''[http://www.apsnet.org/online/feature/ergot/0218-01F.pdf](on [[sorghum]]). ''C. purpurea'' can affect a number of cereals including [[rye]] (its most common host), [[triticale]], [[wheat]] and [[barley]]. It affects [[oat]]s only rarely.
There are three races or varieties of ''C. purpurea'', differing in their host specificity [http://www2.biomed.cas.cz/~pazouto/purpurea.htm]:
*G1 — land grasses of open meadows and fields;
*G2 — grasses from moist, forest, and mountain habitats;
*G3 (''C. purpurea'' var. ''spartinae'') — salt marsh grasses (''Spartina'', ''Distichlis'').
== Life Cycle ==
An '''ergot kernel''' called a sclerotium develops when a floret of flowering grass or cereal is infected by a [[spore]] of fungal species of the genus ''Claviceps''. The infection process mimics a [[pollen]] grain growing into an [[ovary (plants)|ovary]] during [[fertilization]]. Because infection requires access of the fungal spore to the [[Gynoecium|stigma]], plants infected by ''Claviceps'' are mainly [[outcrossing]] species with [[Anemophily|open flowers]], such as rye (''[[Secale|Secale cereale]]'') and [[Lolium|ryegrasses]] (genus ''Lolium''). The proliferating fungal [[mycelium]] then destroys the plant ovary and connects with the [[vascular bundle]] originally intended for [[seed]] nutrition. The first stage of ergot infection manifests itself as a white soft tissue (known as [[sphacelia]]) producing sugary [[Honeydew (secretion)|honeydew]], which often drops out of the infected grass florets. This honeydew contains millions of [[asexual reproduction|asexual]] spores ([[conidia]]) which are dispersed to other florets by [[insect]]s. Later, the sphacelia convert into a hard dry sclerotium inside the husk of the floret. At this stage, [[alkaloid]]s and [[lipid]]s accumulate in the sclerotium.
''Claviceps '' species from tropic and subtropic regions produce macro- and microconidia in their honeydew. Macroconidia differ in shape and size between the species, whereas microconidia are rather uniform, oval to globose (5x3μm). Macroconidia are able to produce secondary conidia. A germ tube emerges from a macroconidium through the surface of a honeydew drop and a secondary conidium of the oval to pearlike shape is formed to which the contents of the original macroconidium migrates. Secondary conidia form white frost-like surface on honeydew drops and are spread by wind. No such process occurs in ''Claviceps purpurea'', ''Claviceps grohii'', ''Claviceps nigricans'', and ''Claviceps zizaniae'', all from North temperate regions.
When a mature sclerotium drops to the ground, the fungus remains dormant until proper conditions trigger its fruiting phase (onset of spring, rain period, etc.). It germinates, forming one or several [[fruiting bodies]] with head and [[stipe (mycology)|stipe]], variously colored (resembling a tiny [[mushroom]]). In the head, threadlike [[sexual reproduction|sexual]] spores are formed, which are ejected simultaneously, when suitable grass hosts are flowering. Ergot infection causes a reduction in the yield and quality of grain and hay produced, and if infected grain or hay is fed to livestock it may cause a disease called [[ergotism]].
Black and protruding sclerotia of ''C. purpurea'' are well known. However, many tropical ergots have brown or greyish sclerotia, mimicking the shape of the host seed. For this reason, the infection is often overlooked.
== Effects on humans and animals ==
{{Main|Ergotism}}
The ergot sclerotium contains high concentrations (up to 2% of dry mass) of the [[alkaloid]] [[ergotamine]], a complex molecule consisting of a tripeptide-derived cyclol-lactam ring connected via [[amide]] linkage to a lysergic acid (ergoline) moiety, and other alkaloids of the [[ergoline]] group that are [[biosynthesis|biosynthesized]] by the fungus.<ref name="Tudzynski">{{cite journal|author=Tudzynski P, Correia T, Keller U|year=2001|title=Biotechnology and genetics of ergot alkaloids|journal= Appl Microbiol Biotechnol.|volume=57|pages=4593–4605|pmid=11778866|doi=10.1007/s002530100801}}</ref> Ergot alkaloids have a wide range of [[biological activity|biological activities]] including effects on [[circulatory system|circulation]] and [[neurotransmission]].<ref name="Eadie">{{cite journal|author=Eadie MJ|year=2003|title=Convulsive ergotism: epidemics of the serotonin syndrome?|journal= Lancet Neurol.|volume=2|pages=429–434|pmid=12849122|doi=10.1016/S1474-4422(03)00439-3}}</ref>
[[Ergotism]] is the name for sometimes severe pathological syndromes affecting humans or animals that have ingested ergot alkaloid-containing plant material, such as ergot-contaminated grains. The common name for ergotism is "St. Anthony's Fire", in reference to the symptoms, such as severe burning sensations in the limbs.[http://www.medicinenet.com/script/main/art.asp?articlekey=14891] These are caused by effects of ergot alkaloids on the [[circulatory system|vascular system]] due to [[vasoconstriction]] of blood vessels, sometimes leading to [[gangrene]] and loss of limbs due to severely restricted blood circulation. The neurotropic activities of the ergot alkaloids may also cause [[hallucinations]] and attendant irrational behaviour, convulsions, and even death.<ref name="Tudzynski"/><ref name="Eadie"/> Other symptoms include strong [[uterus|uterine]] contractions, [[nausea]], [[seizure]]s, and unconsciousness. Historically, controlled doses of ergot were used to induce [[abortion]]s and to stop maternal bleeding after childbirth. Ergot alkaloids are also used in products such as [[Cafergot]] (containing [[caffeine]] and [[ergotamine]] or [[ergoline]]) to treat migraine headaches. Simple ergot extract is no longer used as a [[pharmaceutical]] preparation.{{fact|date=October 2007}} Monks of the order of St. [[Anthony the Great]] specialized in treating ergotism victims with balms containing tranquilizing and circulation-stimulating plant extracts; they were also skilled in amputations.{{fact|date=June 2007}}
In addition to ergot alkaloids, ''Claviceps paspali'' also produces [[tremorgen]]s (paspalitrem) causing "paspalum staggers" in cattle.{{fact|date=June 2007}} Ergot alkaloids are also produced by fungi of the genera ''[[Penicillium]]'' and ''[[Aspergillus]]'', notably by some isolates of the human pathogen ''[[Aspergillus fumigatus]]'',<ref name="Rao">{{cite journal|author=Rao KK, Rao S|year=1975|title=Effect of tweens on the production of ergot alkaloids by Aspergillus fumigatus|journal= Folia Microbiol.|volume=20|pages=418–422|pmid=1104424|doi=10.1007/BF02877045}}</ref> and have been isolated from plants in the family [[Convolvulaceae]], of which [[morning glory]] is best known.
Ergot contains no [[lysergic acid diethylamide]] (LSD) but instead contains [[ergotamine]], which is used to synthesize [[lysergic acid]], an analog of and precursor for synthesis of LSD. Moreover, ergot sclerotia naturally contain some amounts of lysergic acid. <ref name="Correia et al">{{cite journal|author=Correia T, Grammel N, Ortel I, Keller U, Tudzynski P.|year=2001|title=Molecular cloning and analysis of the ergopeptine assembly system in the ergot fungus Claviceps purpurea|journal= Chem Biol.|volume=10|pages=1281–1292|pmid=14700635|doi=10.1016/j.chembiol.2003.11.013}}</ref>
In the [[January 4]], [[2007]] issue of the [[New England Journal of Medicine]], a paper was published documenting a British study of over 11,000 [[Parkinson's Disease]] patients. The study found that two ergot-derived drugs, [[Pergolide]] and [[Cabergoline]], commonly used to treat Parkinson's Disease may increase the risk of leaky heart valves by up to 700%. <ref>[http://content.nejm.org/cgi/content/abstract/356/1/29 NEJM - Dopamine Agonists and the Risk of Cardiac-Valve Regurgitation<!-- Bot generated title -->]</ref>
== Speculations ==
[[Image:Ergot01.jpg|thumb|Ergot on wheat spikes]]
The disease cycle of the ergot fungus was first described in the 1800s, but the connection with ergot and epidemics among people and animals was known several hundred years before that.
Human poisoning due to the consumption of rye bread made from ergot-infected grain was common in Europe in the [[Middle Ages]]. The epidemic was known as [[Saint Anthony's Fire]] or [[ignis sacer]].
[[Linnda R. Caporael]] posited in 1976 that the hysterical symptoms of young women that had spurred the [[Salem witch trials]] had been the result of consuming ergot-tainted rye. <ref>"Ergotism: The Satan Loosed in Salem?", '''Science''' Vol. 192 (2 April 1976), pp. 21-26. See: http://web.utk.edu/~kstclair/221/ergotism.html</ref> However, her conclusions were later disputed by Nicholas P. Spanos and Jack Gottlieb, after a review of the historical and medical evidence. <ref>"Ergotism and the Salem Village Witch Trials", '''Science''', Volume 194, Issue 4272, pp. 1390-1394</ref> Other authors have likewise cast doubt on ergotism having been the cause of the Salem Witch Trials. <ref name="Woolf">{{cite journal|author=Woolf A|year= 2000|title=Witchcraft or mycotoxin? The Salem witch trials|journal=J Toxicol Clin Toxicol|volume=38|pages=457–460|pmid=10930065|doi=10.1081/CLT-100100958}}</ref>
The [[Great Fear]] in France during the [[French Revolution|Revolution]] has also been linked by some historians to the influence of ergot.
British author [[John Grigsby]] claims that the presence of ergot in the stomachs of some of the so called 'bog-bodies' - Iron Age human remains from peat bogs N E Europe such as [[Tollund Man]] - reveals that ergot was once a ritual drink in a prehistoric fertility cult akin to the [[Eleusinian Mysteries]] cult of ancient Greece. In his book [[Beowulf and Grendel (book)|Beowulf and Grendel]] he argues that the Anglo-Saxon poem [[Beowulf]] is based on a memory of the quelling of this fertility cult by followers of [[Odin]]. He states that Beowulf, which he translates as ''barley-wolf'', suggests a connection to ergot which in German was known as the 'tooth of the wolf'.
[[Kykeon]], the beverage consumed by participants in the ancient Greek mystery of [[Eleusinian Mysteries]], might have been based on hallucinogens from ergot.
Currently, [[rye]] grain is infected to produce ergot sclerotia. Male sterile rye is often used, as the pollen from fertile rye competes with the fungal conidia.
== Poisonings mistaken for ergotism ==
Poisonings due to consumption of seeds treated with [[Mercury (element)|mercury]] compounds are sometimes misidentified as ergotism, such as the case of mass-poisoning in the French village [[Pont-Saint-Esprit]] in 1951:
<blockquote>
The mass poisoning which took place in the French town of Pont-St. Esprit in 1951 has been widely presented in the lay and scientific press as an example of ergotism. While the poisoning was traced to bread, ergotism was not the cause of the syndrome, which was due to a toxic mercury compound used to disinfect grain to be planted as seed. Some sacks of grain treated with the fungicide were inadvertently ground into flour and baked into bread. [[Albert Hofmann]] arrived at this conclusion after visiting Pont-St. Esprit, and analyzing samples of the bread (which contained no ergot alkaloids) and autopsy samples of four of the victims who succumbed (Hofmann 1980; Hofmann 1991). On the other hand, Swedish toxicologist Bo Holmstedt insists the poisoning was in fact due to ergotism (Holmstedt 1978).…<ref>[[Jonathan Ott]], ''Pharmacotheon: Entheogenic Drugs, their Plant Sources and History'' (Kennewick, W.A.: Natural Products Co., 1993), pg. 145. See also Dr. [[Albert Hofmann]], ''LSD: My Problem Child'' (New York, N.Y.: McGraw-Hill Book Company, 1980), [http://www.lycaeum.org/books/books/my_problem_child/chapter1.html Chapter 1: "How LSD Originated," pg. 6.]</ref>
</blockquote>
As Dr. Simon Cotton (member of the Chemistry Department of [[Uppingham School]], U.K.) notes, there have been numerous cases of mass-poisoning due to consumption of [[Mercury (element)|mercury]]-treated seeds:
<blockquote>
More horrifying than this were epidemics of poisoning, caused by people eating treated seed grains. There was a serious epidemic in Iraq in 1956 and again in 1960, whilst use of seed wheat (which had been treated with a mixture of [[ethylmercury|C<sub>2</sub>H<sub>5</sub>HgCl]] and [[phenylmercuric acetate|C<sub>6</sub>H<sub>5</sub>HgOCOCH<sub>3</sub>)]] for food, caused the poisoning of about 100 people in West Pakistan in 1961. Another outbreak happened in Guatemala in 1965. Most serious was the disaster in Iraq in 1971–1972, when according to official figures 459 died. Grain had been treated with methyl mercury compounds as a fungicide and should have been planted. Instead it was sold for milling and made into bread. It had been dyed red as a warning and also had warning labels in English and Spanish that no one could understand.<ref>See Simon Cotton, B.Sc., Ph.D., [http://www.chm.bris.ac.uk/motm/dimethylmercury/dmmh.htm "Dimethylmercury and Mercury Poisoning"], ''Molecule of the Month'' (''[http://www.chm.bris.ac.uk/motm/motm.htm MOTM]''; published on the School of Chemistry, [[University of Bristol]], U.K. website), October 2003.</ref>
</blockquote>
== References ==
{{reflist}}
== External links ==
{{commons|Claviceps purpurea|Ergot}}
* http://www.entheology.org/edoto/anmviewer.asp?a=37&z=5
* http://www.ext.nodak.edu/extpubs/plantsci/crops/pp551w.htm
* [http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=15933008 Abundant Respirable Ergot Alkaloids from the Common Airborne Fungus Aspergillus fumigates]
* [http://www.pbs.org/wnet/secrets/case_salem/index.html PBS Secrets of the Dead: "The Witches Curse" (concerning the Salem trials and ergot)]
* [http://content.nejm.org/cgi/content/short/356/1/29 New England Journal of Medicine - Dopamine Agonists and the Risk of Cardiac-Valve Regurgitation]
* [http://www.healthday.com/Article.asp?AID=600564 HealthDay - Parkinson's Drugs Can Damage Heart Valves]
{{Ergolines}}
[[Category:Ascomycota]]
[[Category:Psychoactive mushrooms]]
[[Category:Natural sources of lysergamides]]
[[Category:Medicinal fungi]]
[[Category:Parasitic fungi]]
[[Category:Plant pathogens and diseases]]
[[Category:Cereal diseases]]
[[Category:Barley diseases]]
[[Category:Rye diseases]]
[[Category:Triticale diseases]]
[[Category:Wheat diseases]]
[[Category:Abortifacients]]
{{Link FA|ro}}
[[cs:Paličkovice nachová]]
[[da:Meldrøjer]]
[[de:Mutterkorn]]
[[el:Ερυσίβη]]
[[es:Claviceps purpurea]]
[[fa:بیماری ناخنک]]
[[fr:Ergot du seigle]]
[[it:Ergot]]
[[nl:Moederkoorn]]
[[ja:麦角菌]]
[[no:Meldrøye]]
[[pl:Buławinka czerwona]]
[[pt:Esporão do centeio]]
[[ro:Cornul secarei]]
[[ru:Спорынья]]
[[sk:Kyjanička purpurová]]
[[fi:Torajyvä]]
[[sv:Mjöldryga]]
[[tr:Çavdar mahmuzu]]
[[uk:Ріжки маткові]]
[[zh:麦角]]