FFF Exam 2 Study Guide Questions

What are the three ergot alkaloids discussed and what effects do they have on animals?

- Ergotamine: a vasoconstrictor, causes "dry gangrene" - Ergonovine: causes spontaneous abortion - Ergine (aka lysergic acid amide - LSA): causes hallucinations and uncontrollable muscle spasms

What is ergotism? What are the symptoms?

- Gangrenous: caused by ergotamine, complete constriction of blood flow to the limbs, rot and loss - Convulsive: caused by ergine, attacks neurosystem, uncontrollable twitching and limb distortion, seizures etc. can be fatal. - Define ergot, disease in plants - Ergotism, the disease in humans.

What other historical events may have been due to ergotism? What symptoms did people have that led historians to think ergotism could be the cause?

- Witchcraft Hysteria - Salem Witch Trials, twitching, barking, screaming etc. for those who lived in river valleys and ate rye bread - hallucinations in 16th-17th Century Europe - Visions of Joan of Arc - Greek mysteries of Eleusis (weeks-long initiation from ergot decoctions) - Hysterical Dancing Mania (people would dance till they dropped?) - Pont-Saint-Esprit (1950s, French village went mad, blaming ergot and mercury)

What are some potential benefits of ergot alkaloids?

- extract used for vascular and migraine headaches, Parkinson's, post-partum bleeding, psychosis, etc. - medicinal cultivation - Hasten childbirth/induce abortions (Middle-age midwives used it) (1807 Physician recommended it) (1823, now only for postpartum)

How to control Laurel Wilt

- quarantine. You couldn't move loracious crops to places where avocados were. After it spread, you couldnt move plants, but now its spread everywhere and quarantining is impractical - watch for, and control the vector. But traps out 'pest sticky cards' to see how many beetles are around. Biocontrol? to find predators who eat the beetle - sanitation of tools and clothes. Infected trees are burned/moved/trying to keep everything free of disease - public education about moving wood. Dogs can sense it first before people can

What are the impacts of laurel wilt?

- their threat to Florida avocado industry, Haas avocados - removal of dead trees costs money - decreased property values with large trees removed - nurseries that sell redbay or other lauraceous plants lose money due to quarantines - lost money from firewood, mulch etc - fire hazard due to dead trees as fuel

What are the lessons that were learned from aflatoxin research?

1. Primary site of action: liver Short term - acute toxicity Long term - chronic deterioration, cancer 2. Animals vary in sensitivity 3. Aspergillus produces more toxin when plants are stressed, drought & diseased 4. Substrate affects toxin production

How is Dutch elm disease managed? In what cases would a tree with this disease even be managed?

1. control beetles by pruning or insecticides 2. fungicide injections 3. root graft breakage. disease management is costly, so usually they just tear it down.

What is Turkey X Disease? What was the cause?

100,000 turkeys in England dead in 1960, aflatoxin (Aspergillus flavus) and fungus toxins combined

Who is Alexander Hofman? What did he synthesize from an ergot alkaloid precursor? What were the effects of this compound on him?

A Swiss pharmaceutics scientists, developing circulatory stimulation drug. He synthesized LSD in 1938, then resynthesized and ate it in 1943, then tripped out on a super high dosage.

Chestnut Blight- what are the hosts?

American and Chinese chestnut trees

Is the soybean rust fungus asexual only or reproducing sexually?

Asexual, likes warmer regions

Is the coffee rust fungus asexual only or reproducing sexually?

Asexually

what fungus produces aflatoxin? What are the symptoms? What animals are most affected? What crops are most often contaminated?

Aspergillus flavus and parciticus? But not oryzae?

What are the alternate hosts of wheat stem rust?

Barberry, makes P. graminis stem rust sexual on their leaves

What causes fescue foot, fescue toxicosis and ryegrass staggers? What are the plants and fungus involved? What compounds are produced by the fungus? What effect do these conditions have on livestock and other animals?

Caused by ergot alkaloids from a different fungus, Epichloe species. Fescue is a pasture grass? Effects on livestock: ‣ lower food intake ‣ lower weight gain ‣ reduced reproductive performance ‣ lower milk production

What is the causal organism or ergot and ergotism?

Claviceps purpurea, "Purple Clubhead". - causes a condition known as St. Anthony's Fire - was likely responsible for the Salem Witch Trials - can cause an affected person's limbs to fall off

What are the sclerotia and club heads and what are their roles in the survival of the fungus?

Clubheads are the spores that are produced and are shot into the air and wind disperse. Sclerotia/um are the brown worm things that germinate in warm weather and fall off in autumn and grow in the soil's surface.

What are the alternative hosts of coffee rust?

Coffee plants, arabica vs robusta

What crops are most likely to be contaminated with aflatoxin?

Corn, peanut, cottonseed meal, and other animal feeds

Why was ergotism a problem for peasants in the middle ages? What crop is most affected? Why was it called St. Anthony's Fire?

Crops effected are wheat, oat, barley, rye, wild rice, etc when they are producing seeds. Ergotamine would infect poor people who only really ate those crops, and they would feel like they are on fire, and turned to the Church for help.

How is dogwood anthracnose managed? What conditions make the disease better or worse?

Effects developing shoots, leaves. Causes cankers throughout Appalachia. If trees can tolerate the disease, they can bounce back. ‣ Favored by wet rainy weather ‣ Do not transplant trees and only buy from a reputable nursery ‣ Plant in sunny areas ‣ Prune diseased trees ‣ Maintain healthy trees - water and fertilize ‣ Fungicides may be warranted

Dutch Elm Disease- what are the hosts?

Elm trees.

What is an endophyte? What are the benefits of the fescue and ryegrass endophyte?

Endophytes: Symbiotic fungi living within plant tissues, but thereare no symptoms, they do not cause disease in the plant. • greater stand persistence than endophyte-free fescue • increased resistance to insect herbivory • reduced herbivory from grazing livestock • increased resistance to plant pathogens • increased drought tolerance • increased production of tillers • increased photosynthetic rate • increased tolerance of nutrient limiting conditions

Where did coffee rust originate?

Ethiopia area of Eastern Africa, but first major outbreak is in Sri Lanka.

Why are there frequent outbreaks in dogs associated with contaminated dog food?

Fatal levels of aflatoxin in pet food coming from Oklahoma plant. Largely dogs are at risk because they have no variation in their diet.

Where did wheat stem rust originate?

Fertile crescent, found in 1300BC archeological digs

What is the Puccinia pathway of wheat stem rust?

Fertile crescent? Kinda looks like tornado alley. Texas and up horizontally, Mid-west USA.

what fungus produces fumonisin? What are the symptoms? What animals are most affected? What crops are most often contaminated?

Fusarium- a mold. Found in corn. Porcine pulmonary edema. Causes neural tube defects and esophageal cancer in humans. Equine leukoencephalomalacia, a.k.a. "Hole in the Head Disease" Alexander Haig??????

what fungus produces trichothecenes (T-2 and DON)? What are the symptoms? What animals are most affected? What crops are most often contaminated?

Fusarium- a mold. Makes the toxins. T-2: skin pain, vomiting, diarrhea,complete degeneration of bone marrow, and eventually death, played a role in accusing the soviet union of providing the toxin. DON- nausea, fever, headaches, and vomiting. current problem in U.S. grain crops.

what fungus produces zearalenone? What are the symptoms? What animals are most affected? What crops are most often contaminated?

Fusarium- a mold. mimics action of estrogen, causes abnormal development of reproductive organs. Animals? Crops? Wheat, barley, oats, and craves.

What are the casual organisms of coffee rust?

Hemileia vastatrix (half smooth, devastating). Mostly on Coffea arabica coffee plants.

What is myrtle rust? Why is it so devastating?

Huge problem in Australia

How are the casual organisms of laurel wilt dispersed? Where throughout the US are they now found?

Infects Redbay trees and Swampbay trees, the laurel wilt comes from a symbiotic relationship between Redbay ambrosia beetle (Xyleborus glabratus) and a fungus called Raffaelea lauricola. When both are in the same place, such as the southeast, there is a lot of laurel wilt. The beetles survive in dead trees.

How are the casual organisms of sudden oak death? Where throughout the US are they now found?

It is an oomycete. Like Phytophera infestans. High risk around the west coast and the appalachian mountains in the US.

What are the alternative hosts of soybean rust?

Kudzu

What are the differences between chronic and acute aflatoxin exposure?

LD50: 0.5-10 mg/kg of body weight, Acute is short term, acute toxicity symptoms, but chronic deterioration can develop cancers etc.

Dutch Elm Disease- what are the symptoms?

Leaf breakage and dieback, the fungi infect the vascular system. Making it difficult to photosynthesize. Look up this disease with APS.

What are the impacts of sudden oak death (Phytophthora ramorum)? Symptoms?

Lethal to oak, beech, tan oak trees, rhodedendron. Infects nursery plants, landscape, and forest. Kills in 6mo-2yr Symptoms: - indescted canbium - bleeding cankers - dieback of foliage ‣ Dead oak trees worsen fire hazard ‣ Many types of wildlife depend on oaks for shelter and food ‣ Oaks are highly valued in urban settings for beauty and shade; add $$ value to property ‣ Trying to stop spread through regulation and testing of ornamental plants shipped interstate

Where did soybean rust originate?

Native to Eastern Asia

What are the alternate hosts of soybean rust?

None

Are mycotoxins a major concern in the US? Why or why not?

Not REALLY a problem in the US cause we have strict regulations, but it is a problem in other countries with imports. Highly varied diet.

Dutch Elm Disease- what are the casual organisms? Are they fungi? Are they vectored? Whats the vector?

Ophiostoma ulmi and O. novo-ulmi, true fungi. 3 bark beetles vectors. Their relationship is symboitic.

Chestnut Blight- where is its origin, where was the disease introduced to? Is it reproducing sexually in the US?

Origin also Asia? China? Introduced to the US via lumber trade? Sexually reproduces through ascospores.

what fungus produces ochratoxin? What are the symptoms? What animals aremost affected? What crops are most often contaminated?

Penicillium toxins, some Aspergillus. Causes human chronic kidney disease and is a carcinogen? Infects cereals, coffee, dried fruit, figs, tree nuts, grapes and red wine. Accumulated in muscle, meat.

What are the casual organisms of soybean rust?

Phakopsora pachyrhizi and P. meibomiae

What is aflatoxicosis?

Poisoning, especially of the liver that results from ingestion of aflatoxins from contaminated food

What is one of the solutions used to control the problem of the toxin while allowing the endophyte to provide the plants with its benefits?

Producing grass that has the endophyte to help it grow, but taking out the ergot alkaloid byproduct. Produced as a mycotoxin

What are the casual organisms of wheat stem rust?

Puccinia graminis = stem rust P. recondita = leaf rust P. striiformis = stripe rust

How is soybean rust managed?

Rust scouting and monitoring programs

What are mycotoxins?

Secondary metabolite produced by a fungus and toxic to humans and other animalsAre produced on food and accidentally ingested. NOT mushroom ones.

Dutch Elm Disease- where is its origin, where was the disease introduced to? Is it reproducing sexually in the US?

Somewhere in Asia? First identified in the Netherlands.

Chestnut Blight- what are the symptoms?

The fungus gets into the tree via a wound in the bark, the fungus then grows around the tree and girdles the tree causing death, orange oxilate oxidase produced.

What makes a fungus a rust fungus?

They are obligate biotrophs. Meaning they require a living plant host for nutrition. They are host specific because they need to trick host against defenses. So many spores, millions in the rust pustules. They have special structures. Produce different spore types that are all closely related to each other. They also have teliospores and epidermis tissue. ‣ White pine blister rust ‣ Fusiform rust on Oak, produces hair-like teliospore structures and Pine, produces galls ‣ Cedar apple rust, infects red cedars, juniper trees, and apple orchards. ‣ Hemlock needle rusts

Why do fungi produce mycotoxins?

They produce because - Increase competitiveness against other microbes • Avoid consumption by insects/or act as insecticides • Enhance survival probability under certain environmental stresses • Virulence factors • Dumping byproducts • No one thinks that fungi are making toxins to harm mammals - collateral damage - Selective advantage from secondary metabolites, enhanced growth of the producer, benefits it with nutrient sequestration for the surrounding environment.

How is wheat stem rust managed?

Trying to breed rust resistant varieties. Take away barberry plants, like the eradication programs in 1930s.

What were the impacts of chestnut blight? How did the virus impact Cryphonectria parasitica? Why did it not work very well to control the fungus in the US? What are the two ways researchers trying to create blight-resistant American chestnut trees?

Two ways: - Crossbreeding, but that takes a long time - GMO chestnuts created from a resistant gene from wheat into the American chestnut, and the product shows better resistance with a higher percentage of American chestnut

Is the wheat stem rust fungus asexual only or reproducing sexually?

Typically asexual, unless on barberry.

What are the alternate hosts of coffee rust?

Unknown

What are the alternative hosts of wheat stem rust?

Wheat plants and similar grasses.

How have mycotoxins been used as weapons of mass destruction? Which toxin was used? Why?

Yellow Rain, T-2 toxin.

Chestnut Blight- what are the casual organisms? Are they fungi? Are they vectored? Whats the vector?

cryphonectria parasitica. fungus.

How is ergot controlled in the field?

manage through crop rotation (breakup lifecycle with a non-host), fall plowing (because the ergot only survives on top of soil) and rigorous screen detection/inspection to remove the sclerotia

How can we prevent, reduce, or control mycotoxin contamination of food?

• Control the fungi in the field • Control the fungi in storage • Control insects (wounding) in the field and in storage • Test grains, peanut butter, juice, etc., for mycotoxins • Food additives • Rigorous government and industry inspection • Improved storage facilities • Heat treatment for some • Chemical treatment • Plant breeding

How is coffee rust managed?

• Defoliate the over-story trees, however that increase CO2 and decreases carbon fixation • Coffee grows better at a higher elevation now that climate change is occuring, so they try to grow at higher hills • Coffee growers try to grow coffea robusta instead but its not as economically beneficial

Management strategies for rust diseases in general

• Plant resistant varieties- best! ◦ Issue: costly, takes time to develop, can't always plant resistant varieties • Eradicate alternate host (and alternative hosts, if possible) ◦ Issue: potentially hard to accomplish and costly • Quarantine ◦ Issue: Hard to be 100% effective • Fungicides ◦ Issue: not always economically feasible

What is the destructive race of wheat stem rust? Why is it such a concern?

◦ Stem Rust/Black stem rust ‣ Puccinia graminis ‣ very host-specific, only really effects wheat and grasses -Ug99, Kenya, causing 80%