The cereal rust that occurred in Europe in ancient times,
caused by the fungus Puccinia, and others.
Several epidemics of ergotism, both gangrenous and
convulsive, have been reported since 600 b.C., killing thousands
of people. It was caused by a fungus which affected rye grains
and produced rigid structures like a spur of a rooster. In this
structure, there are several alkaloids, among them LSD. When
the contaminated rye was harvested, the bread was prepared
and baked. The temperature of the ovens killed the fungus but
did not deactivate the alkaloids, causing the disease. It was only
in 1853 that Louis Tulasne, mycologist and illustrator, conclud-
ed that the fungus Claviceps purpurea present among the rye
grains, and not the rye itself, was the causative agent of the dis-
ease.
The Irish potato famine around 1846 caused the death
of more than two million people and the emigration of one mil-
lion was due to the potato late blight, an infection caused by the
“fungus” Phytophthora infestans in potato crops of that region.
This tuber was the main food of the population and the weather
conditions that year were adequate for the fungus development.
So, the epidemic was devastating, decimating the crops over-
night, culminating with the destruction of 80% of the production.
Another rust in the epidemic scenario, was the fungus
Hemileia vastatrix, known as the coffee rust, which decimated
the coffee plantations until 1870 in Ceylon (now Sri Lanka), forc-
ing the Englishmen to seek another hot and stimulating drink
to withstand the harsh winters to which they were subjected. It
was for this reason that they found the famous tea, the English
tea. This same fungus appeared in coffee plantations in Brazil
a hundred years later in the 1970s, causing alarm and bringing
losses to the country’s coffee plantations. Nowadays, farmers
live well with the disease, although production losses caused by
rust are always worrying.
In 1943, the fungus Bipolaris oryzae (formerly known as
Helminthosporium oryzae) affected the rice crops and caused
the loss of up to 90% of the production in Bengal (between In-
dia and Bangladesh), which was involved by the war, bringing to
mass starvation and death from malnutrition between 1.5 to 3
million people during that period.
In Brazil, we have the interesting report of “rubber tree
leaf disease”, a disease caused by the fungus Pseudocercospo-
ra ulei (= Microcyclus ulei) that affects the leaves of the Rubber
tree. In 1934, it provoked a violent epidemic by decimating the
rubber trees of the Fordlândia town, in the state of Pará. This
city was built by the industrialist Henry Ford, in the Amazon jun-
gle, to serve as a rubber production area for his automobile in-
dustries. An even greater new plantation was established, later
in the city of Belterra, and in 1942 it was also ravaged by the fun-
gus. Fordlândia and the other plantations had to be abandoned.In 1970 the fungus Bipolaris maydis (= Helminthospori-
um maydis) caused the loss of 20 million tons of maize in the
United States, and Americans only understood the severity of
the problem when the numbers were converted into a loss of 30
billion hamburgers.From then on, numerous epidemics and worries about
fungi in plants have taken place in society and some that have
been better divulged could be highlighted and documented, as
follows:- Sugarcane smut, in 1981, caused by the fungus Spor-
isorium scitamineum (= Ustilago scitaminea); - Sugarcane brown rust in 1986, disease caused by the
fungus Puccinia melanocephala; - The famous witches` broom disease from 1989 to
2000, caused by the fungus Moniliophthora perniciosa (= Crin-
ipellis perniciosa) that caused a profound economic change in
the country’s cocoa production; - The citrus black spot, in 1992, caused by the fungus
Guignardia citricarpa (= Phyllosticta citricarpa); - Soybean stem canker, in 1993, caused by the fungus
Diaporthe phaseolorum; - Sugary disease or Ergot disease of sorghum in 1995,
caused by the fungus Claviceps africana (= Sphacelia sorghi); - The sigatoka disease and black sigatoka of banana
tree, in 1944 and 1998, diseases caused by the fungi Mycos-
phaerella musicola (= Pseudocercospora musae) and Mycos-
phaerella fijiensis (= Paracercospora fijiensis), respectively; - The soybean rust in 2000, disease caused by the fun-
gus Phakopsora pachyrhizi and, - The orange rust of sugar cane, in 2000, a disease
caused by the fungus Puccinia kuehnii, among others.
In contrast to plant diseases caused by fungi, other
forms of beneficial interactions are found, such as mycorrhizal
associations. Mycorrhizae are interactions of fungi with the
roots of plants where there is an exchange of nutrients that
favour the development and survival of both, especially in en-
vironments less favourable to the absorption of nutrients by
plants. The lichenized fungi or commonly known as lichens are
associations between algae and fungi in a single body, provid-
ing such intimacy that there are exchanges between nutrients
solubilized by the partner fungus with nutrients synthesized
by the algae. Many chemicals produced by both have already
been identified(11), although little is known about the active