PLPA Final Exam

Powdery mildew of grape

1845 England, then France, Germany, Italy Destroyed 80% of crop Controlled with Sulfur and Lime Probably came from NA, common on wild grapes, on shipped stock for hybridization

Downy mildew of grape

1865 Europe Nearly destroyed European wine industry Came from NA on stock exported for insect resistance 1882 first fungicide developed Noticed lush, disease-free grapes, sprayed with copper sulfate and lime Called Bordeaux mixture

Fusarium Wilt

1890 - first reported in Panama Outbreak in 1960s that essentially wiped out Gos Michel variety Replaced by Cavendish cultivar which was thought immune disease

Chestnut Blight distribution

1926 reported throughout native range of American chestnut 1940 had destroyed all chestnut trees in the E US major forest tree had been reduced to a multiple stem shrub 1912 Plant Quarantine Act passed to reduce the chances of such a catastrophe happening again

Cavendish bananas

Banana growers turned to this breed that was immune to the Panama disease It's a smaller, less tasty fruit but one capable of surviving global travel and able to grow in infected soils

Chestnut Blight

By 1940-50s had destroyed all chestnut trees in the eastern US Reduced it to understory species Host: American chestnut Introduced pathogen: 1904 New York Zoological Garden where there was a rapid and sudden death of many branches, stems, and trees No control attempts (chemical treatments, clearing, burning around infection sites) successful Signs: fruiting bodies, ascomycota, perithecium Infects trunks and branches (above ground parts of tree) Enters through fissures/wounds of bark Grows in and under the bark, girdling the cambium Kills tree above point of infection 2-10 years entire tree dead Not uncommon to find many cankers on the tree Dispersal: animals, insects, rain Fairly specific host range Cannot survive above ground Roots continue to live and send up stump sprouts Stump sprouts grow until infected stump re-sprouts again

Pathogenicity and Ecology of Panama Disease

Casual agent of Fusarium wilt Polycyclic disease Soil-borne pathogen Affects plants' vascular system thus hinders water uptake Other: inducing pre-programmed cell death Hyphae penetrate lateral roots of host

Effects of Potato Famine

Changed demographics, relations of Ireland, England US - ports of arrival ~25% Irish (Boston, New York, Philadelphia) Many Irish families were afraid of another famine, and continued to leave Ireland for places like Canada There was strong resentment between the Irish and English 1861 Anton DeBary showed causal agent, Phytophthora infestans Beginning of plant pathology disciplineAdditional outbreaks.....but diets more diverse Pathogen still causes problems today

Current Uses of Ergot

Ergot alkaloids known to have good uses e.g. induce labor, blood constriction during childbirth Ergonovine is used to control postpartum hemorrhage and cause contraction of the uterus. -Chinese and European midwives are reported to have use ergots with alkaloids in the 1500s. Ergotamine, is prescribed for the management of migraines. Today dopamine enhancing ergot derivatives are sold in pharmacies around the world (Parkinson's Disease)

Present Impact of Ergot

Ergotism is now rare. A floatation method has been devised to remove any ergot from seed.-30% potassium chloride is poured over the Rye where the buoyant ergot and will float to the top and can be skimmed off and the seeds planted. After harvested, the field is deeply ploughed so that the ergot will not germinate. A different crop, not susceptible to rye can then be rotated to break the cycle There has never been a variety of Rye developed that is resistant to ergot.

Food Exports in England

Exports of dairy, grains, meats, vegetables from Ireland to European markets continued 1846 finally allowed import of corn, chicken feed To many in Ireland, biggest insult was not that England didn't provide much aid, but that the English continued to take taxes and food as Irish starved Soldiers would help landlords collect taxes and do evictions, while also guarding the grain ships from the starving poor

Salem Witch Trials

Fueled by the religious extremist Puritanical faith Hardships such as crop failure, livestock losses, or the death of children were viewed as punishment from God. 150 people accused, 19 were hanged, 4 died in prison, and one 80 year old was crushed to death by stones

Ergot of Rye

Fungus infects the flowers with hard resting structures (sclerotia) Sclerotia fall to the ground and lay dormant (overwinter) then germinate in the spring. Sclerotium produce fruiting body with asci, ascospores. Causes disease on plants, but typically does not kill the plant or reduce the yield of the grain substantially

Claviceps Toxins

Fungus produces a deadly syndrome called ergotismin humans and animals. Caused by toxic chemicals in the fungus, called ergot Oldest identified mycotoxin in humans Contaminated foods may cause vomiting, diarrhea, hallucinations, gangrene, and alternating burning and cold sensations Convulsive ergotism Gangrenous ergotism

Late Blight of the Potato

Fungus survived as hyphae in previously infected potatoes and plant parts As warmed in spring, source of new infections Spread during rains and infected new plants Weather in 1845-6 was favorable for pathogen, wet and cool

Antifungal Infection Prevention

Good hygiene is essential Keep skin dry because fungi survive in damp, dark places Never share personal items Treat open wounds immediately and cover with gauze Avoid exposure from contaminated areas (poultry, farms, bat caves) When necessary, wear protective clothing, gloves, dust masks, or respirators to avoid contact or inhalation of these infectious organisms

Fusiform Rust

Grows on stems, branches, leaves, needles, cones Obligate parasites Native, but still causes problems because of forestry in the SE and monoculture Have to breed for resistance in order to control it

Dutch Elm Fungus

Imported pathogen Both sexual and asexual state have spores that are formed in sticky masses so they stick to insects for dispersal

"Coffee Rust"

In the 1800s, this fungal disease devastated the British coffee plantations in Ceylon Caused British to switch to growing tea

Pathogen symptoms

Indication of disease by reaction of the host Ex: lesions, cankers

Pathogen signs

Indication of disease from direct observation of a pathogen or its parts Ex: the fungus

Spread and dissemination of Panama Disease

Infected plant (not fruit) material Contaminated soil Tools and equipment (improper sanitation methods) Surface water Rainfall caries spores and infected tissue along irrigation ditches Infected suckers are symptomless carriers

Dutch Elm Disease

Killed many of the NA elm trees in 1920-40 Still trying to control the disease Changed the way we plant trees in urban landscapes

Ergotism and Witchcraft

Massachusetts in 1692, when 2 little girls became delirious and displayed convulsions, bizarre skin sensations, garbled speech, and at times appeared to be in a trance. Condition spread through out the town. Townsfolk came to the conclusion that they were the victims of witchcraft.

"Redwoods of the East"

Mature chestnuts could be 600 years old Straight and tall, 100' tall Fast growing (reached half ultimate height by 20th year) Resistant to decay

Stem Rust of Wheat

Monocultures Rust absorbs nutrients from plants Pustules break through the epidermis, interferes with transpiration, can cause desiccation in the plant and lead to shriveled grains Stems are weakened and can cause the plant to fall over, which interferes with harvesting in some cases Can destroy a completely healthy crop within 3 weeks

Candida albicans

Most important disease agent of the Saccharomycetelas seldom isolated outside the bodies of animals known from 58 species including wild and domesticated mammals and birds

Human Pathogens

Most people harbor a yeast(s) as part of our normal intestinal and urogenital mycota May result in severe infection; even systematic (candidiasis)

Insect Vector of Dutch Elm

Native elm bark beetle European elm bark beetle Beetles create galleries, and when they do they inoculate fungus into the tree where it grows, and then it provides food for the beetle larvae Symptoms (beetles): wilting, curling, and yellowing of leaves in upper portion of tree

Spread of Blastomycosis

Occur in Eastern and Midwest NA Wisconsin contains the majority of outbreaks Patients with Blastomycosis in South Carolina usually are located in the Northwestern part of the state Dogs infected, especially hunting dogs

Rust

One of the most destructive groups of plant pathogens Biotroph/obligate parasites One of the earliest records of plant diseases Affects all groups of plants, ancient Historically very important disease in U.S. cultural and breeding practices have been effective

Bananas

One of the top ten food commodities Mass production of genetically identical plants Monoculture agriculture highly susceptible to epidemics

Biotroph/Obligate parasites

Organisms that can live an multiply only on another living organism Ex: powdery mildews

Potato

Originally grown in SA; not native to Europe Brought to Europe in 1500s Became very popular because easy to grow, can grow almost anywhere, and can grow a lot of them Became especially popular in Ireland because farmers had less land

St. Anthony's Fire

Outbreak of ergotism occurred in France. Monks belonging to the Order of St. Anthony established hospitals in southern France, erected to care for the victims Holy Fire came to be called St. Anthony's Fire. Hospitals were symbolically painted red to inform the illiterate

Ergot

Plant disease Claviceps purpurea, plant parasite Disease of cereal grains: rye, wheat, barley grasses Fungal structures, sclerotia, form in grass ovary May contain high levels of 3 types of alkaloids: Effect circulation, neurotransmission; original source from which LSD isolated

Prevention of Rust

Romans created the "Robigo" and "Robigus" to protect wheat from the wheat leaf rust fungus Robigalia festival was held in April to protect the fields from this disease

Dancing Plague of 1518

Strasbourg, France Mrs. Troffea began slowly dancing in the street, after a week over thirty people joined her Disease not from supernatural causes, determined the catch-all treatment for disease, bloodletting, would not work...cure? More dancing, stage constructed, professional musicians came Over 400 dancers a month later, mostly women Plague claimed up to fifteen victims per day. Victims died of exhaustion, heart attack, stroke, constant physical exertion.

Disease

Sustained physiological and/or structural damage to tissues Caused by: biological, nonbiological, and biotic/abiotic stresses

Introduction of Chestnut Blight

Thomas Jefferson imported European or Spanish chestnut and grafted it into native root stocks at Monticello In 1876, a nurseryman in Flushing, NY imported the Japanese chestnut Chinese chestnut brought here from Ichang in 1900 to hybridize for ornamentals and nut production

Symptoms of Dutch Elm Disease (roots)

Trees wilt and die rapidly Disease progresses from base upward

Candida

True yeast Systematic or superficial infections Most common cause of fungal infections worldwide Occur on skin, mouth, or gastrointestinal tract If problems in stomach (mucosal barrier) or immune compromised can cause infection Systematic infection: can be life-threatening; treat with systematic antifungal drugs (hard on organs, antifungal resistance)

Ug99

Type of rust on wheat First discovered in Uganda and has spread to plants that have little resistance to the fungus Able to attack a very common wheat rust resistance gene More than 90% of wheat crops are susceptible to this pathogen Could potentially destroy 80% of the global wheat supply Spores could travel across Arabian sea and into India and Pakistan, areas of major wheat production

Gros Michel

Was the world's export banana until 1965 Sweeter than today's bananas and tasted more like the candy you get out of the candy dispenser at the grocery store

Symptoms of Dutch Elm Disease (beetle)

Wilting, curling, and yellowing of leaves in upper portion of tree

Pathogen

a bacterium, virus, or other microorganism that can cause disease Ex: fungi, fungi-like organisms, bacteria, viruses, nematodes, flowering plants

Madura Foot

causes by fungi or actinomycetes (bacteria that resembles fungi) mainly affects the foot endemic in Tropical and subtropical regions Africa, India, Central America, and South America Usually acquired while performing agricultural work Generally afflicts men between 20 and 40 years old infects subcutaneous tissues Normally starts in the foot or hand and moves up the leg or arm Results in destruction, deformity, and loss of function Occasionally fatal

ring worm

common diagnosis for hair loss in pets

Blastomycosis (Chicago Disease)

common in the eastern and central U.S. and in Africa Often found in decaying wood and abandoned buildings Begins as a lung infection caused by inhalation of the conidia The conidia transform into the yeast form, where they can lead to abscesses in the lungs

systematic

develops when a fungus invades the internal organs (or systems), are extremely difficult to treat, particularly in immunocompromised patients Ex: blastomycosis, Valley Fever, Chicago Disease

Transmission of fungi that cause superficial/cutaneous mycoses

direct contact with infected host direct/indirect contact with infected exfoliated skin or hair in combs, hair brushes, clothing, furniture, theatre seats, caps, bed linens, towels, hotel rugs, and locker room floors depending on the species the organism maybe viable in the environment for up to 15 months increased susceptibility to infection when there is preexisting injury to the skin such as scars, burns, excessive temperature, and humidity

Subcutaneous Mycoses

fungi enter the skin and subcutaneous tissue as a result of traumatic implantation or contamination of open wounds common type of subcutaneous fungus seen worldwide is sporotrichosis many fungi are common soil inhabitants more commonly problems where people don't wear shoes

sporotrichosis (Rose Picker's Disease)

fungus found on rose thorns, hay, spagnum moss, twigs, and soil, often occurs in gardeners, farmers, and others in direct contact with soil chronic infection caused by Sporothrix shenckii results from a soil fungus that penetrates the skin through a wound (rose picker's disease) In very rare cases, the infection can spread to other parts of the body The disease can infect the bones, joints, lungs, and brain Such spreading usually occurs only in people with a weakened immune system These infections can be life-threatening and are difficult to treat

superficial/cutaneous

infection of outer layer of skin, the nails and hair due to their ability to utilize keratin Ex: dermatophytes, athlete's foot, jock itch, ringworm

Mycoces

infections found in or on the body (opportunistic)

Convulsive ergotism

is a nervous dysfunction, victim is twists and contorts their body in pain, trembling and shaking, simulates convulsions accompanied by muscle spasms, confusions, delusions and hallucinations

Systematic Mycoces

may result from breathing in the spores of fungi living in the soil or rotting vegetation patients who are immuno-compromised are predisposed, but they can develop in healthy patients

nail fungus

nails also contain keratin

Candidiasis (Yeast Infection)

normally lives on the skin or mucous membranes, kept in check by bacteria, microorganisms Candida can grow out of control due to central illnesses, stress, medications that disturb the delicate balance Thrush - candida infection of the mouth Vaginal yeast infection Treat with topical antifungal drugs "Candida diet"

Histoplasmosis

occurs throughout the world In U.S., most common in the southeastern, mid-Atlantic, and central states the infection enters the body through the lungs Grows as a mold in the soil, and infection results from breathing in air-born particles before early 1950s, disease symptoms were mistaken for tuberculosis prescribed antibiotics usually worsen the disease due to the lack of competition for the fungus

athlete's foot

occurs where moisture and warm temperatures persist fungus grows in superficial layer of skin In response the basal layer of the skin produces more skin cells than usual, skin becomes thick and scaly as these cells push to the surface

Histoplasmosis symptoms

often none; or variable, overlap other diseases (ex; cough, fever, tuberculosis) may affect lungs, skin Endemic to OH and MS river basins; especially in soil contaminated with bird/bat droppings JOHNNY CASH BOB DYLAN

subcutaneous

penetrate below the skin to involve the subcutaneous, connective, and bone tissue. Infection of subcutaneous tissues from the traumatic implantation of the fungus into the skin Ex: Madura's foot

Coccidioidomycosis (Valley Fever)

soil fungus that produces cold-like respiratory disease in U.S., occurs exclusively in the southwest it can grow in the lung and lead to infections throughout the body symptoms are variable, but often the patient has a reaction to the circulating fungus, producing reddening of the skin known as "desert bumps" Occupational hazards are in those occupations in the exposure of soil dust

American Chestnut

throughout much of chestnut range, most timber volume of any species Major source of tannin for leather production Chestnuts Depended on by wildlife Many species of insects fed on the leaves, flowers, and nuts

Valley Fever symptoms

typically flu-like and recoverable, not serious may spread to brain, bone, especially in suppressed immune systems, African-Americans Endemic in NA & SA where arid, in soil, infects animals thus constant inoculum, outbreaks where soil disturbed Must inhale copious amounts of spores

Gangrenous ergotism

victim may lose parts of their extremities, Causes gangrene to occur by constricting the blood vessels(vaso-constrictor) leading to the extremities. Because of the decrease in blood flow, infections occur in the extremities, accompanied by burning pain.

Uses of Ergot

•Albert Hofman - isolation and purification while working at Sandoz 1943 discovered LSD-25 (by accident) Compounds affect the central nervous system and also cause vasoconstriction which interferes with the neurotransmitter serotonin. Originally prescribed for psychiatric disorders, particularly in the treatment of alcoholic schizophrenia. CIA - mind control

Holy Fire

"Fire" because of the burning sensations, in the extremities, and "Holy"because of the belief that this was a punishment from God. European epidemics, began in the 9thcentury and lasted 800 years May be responsible for some of the geographical boundary of Europe today Holy Roman Empire, ergot poisoning allowed for easy Viking invasion. Result, Empire split into two kingdoms. West Franks became France and the Franks became Germany.