ergot - Life cycle of the fungus, Effects on humans and animals, Speculations

A fungal disease of grasses caused by Claviceps purpurea; forms hard black fruiting bodies (sclerotia) in flower-heads of infected grasses, including cereal crops; sclerotia contain chemicals (alkaloids) which can cause severe poisoning if ingested. (Class: Pyrenomycetes.)

iErgot
Claviceps purpurea
Scientific classification
Kingdom: Fungi Division: Ascomycota Class: Euascomycetes Order: Hypocreales Family: Clavicipitaceae Genus: Claviceps
Species
About 50, including: Claviceps africanum Claviceps fusiformis Claviceps paspali Claviceps purpurea

Ergot is the common name of a fungus in the genus Claviceps that is parasitic on certain grains and grasses.

Life cycle of the fungus

An ergot kernel called a sclerotium develops when a floret of flowering grass or cereal is infected by a spore of Claviceps fungus. The first stage of ergot infection manifests itself as a white soft tissue (known as sphacelia) producing sugary honeydew, which often drops out of the grass florets.

Claviceps species from tropic and subtropic regions produce macro- and microconidia in their honeydew.

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.). 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.

Effects on humans and animals

Ergot contains alkaloids of the ergoline group, which have a wide range of activities including effects on circulation and neurotransmission.

In addition to ergot alkaloids, Claviceps paspali also produces tremorgens (paspalitrem) causing "paspalum staggers" in cattle.

Historically, controlled doses of ergot were used to induce abortions and to stop maternal bleeding after childbirth, but simple ergot extract is no longer used as a pharmaceutical.

Among those who studied ergot and its derivatives was Albert Hofmann, whose experiments led to the discovery of LSD, a powerfully hallucinogenic ergot derivative that affects the serotonin system. Contrary to some rumors, ergot contains no LSD, but there are links between the two substances:

LSD was first synthesised during research on the active ingredients of ergot.

Speculations

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.

Kykeon, the beverage consumed by participants in the ancient Greek mystery of Eleusinian Mysteries, might have been based on hallucinogens from ergot.

Nowadays, rye grain is infected repeatedly to produce ergot.