A fungus is not a plant.

Fungus Animal Plant

Chitin yes yes no

Food storage

glycogen glycogen starch

Multicellular fungi consist of mycelium,which are made up of strands called hyphae.

Hyphae have enormous surface areas.Absorbs food from environment.Prone to drying out.

Most of “body” of fungus is feeding structure.

Only reproductive body typically exposed to air.Thick, fleshy structure of “shroom” prevents drying out.

Reproductive structure produces spores

Ascomycetes havespores in sacs.

Basidiomycetes havespores on clubs.

In fungi, cytoplasm of two individuals fuses, buttheir nuclei may remain separate for a long time.

Fungal phylogeny is a work in progress!No point in learning this now, will change.

Importance of Fungi:

1. Decomposers

2. Mycorrhizae

3. Lichens

4. Economic Impacts

Fungi as decomposers

Basidiomycete fungi are the only organisms that can completely digest the lignin in wood.

Fungi serve an essential role in the carbon cycle.

Adaptations helping with decomposition:

1. Extracellular digestionOnly small molecules can cross plasma membranes.Secreted enzymes break down large molecules.

Adaptations helping with decomposition:

2. Lignin peroxidase

Enzyme catalyzes removalof a single electron; creating ahighly reactive atom.

“Enzymatic combustion”Uncontrolled oxidation reaction breaks up polymer.(Most enzymatic reactions veryspecific, but lignin itself highlyrandom).

Randomness of reaction means that E from oxidation can’t be harnessed.

Adaptations helping with decomposition:

3. Cellulose digestion

By cutting up lignin, fungigain access to cellulose.

The cellulase enzymesdigest cellulose into glucose, which can beused for food.

Importance of Fungi:

1. Decomposers

2. Mycorrhizae

3. Lichens

4. Economic Impacts

Fungi as partners with plants: Mycorrhizae

Importance of mycorrhizae discovered in ‘70’s.Failure of pine plantations key observation.

Fungi as partners with plants: Mycorrhizae

EM fungi on most trees in temperate & boreal forests.

Hyphae penetrate dead leaves, twigs.Release enzymes that cleave peptide bonds.Provide N to plant in exchange for C.

Fungi as partners with plants: Mycorrhizae

AMF important in tropics and grasslands, on 80% of plants. Ancient; fossil from 400 mya.

Provide phosphorus to plant in exchange for C.

Importance of Fungi:

1. Decomposers

2. Mycorrhizae

3. Lichens

4. Economic Impacts

Fungi as colonizers: lichens

Lichens are composed of fungal hyphae and a layer of autotrophic green algae or cyanobacteria

Colonize bare rock following glaciation.

First stage in soil building.

Importance of Fungi:

1. Decomposers

2. Mycorrhizae

3. Lichens

4. Economic Impacts

Of course, the most important economicimpacts are those already mentioned.

Fungi rot crops.

A fungus called ergot is associated with accusations of witchcraft.

Ergot poisoning causes convulsions, shaking, or spasmsand sometimes hallucinations or gangrene.Ergot is the original source from which LSD first isolated.

http://www.botany.hawaii.edu/faculty/wong/BOT135/LECT12.HTM

Fungi are thought to contribute to the worldwidedecline of amphibian populations.

A fungus has caused the

virtual extinction of

the American chestnut.

Note the man, to show

scale.

The first antibiotic was derived from Penicillium.

This is also the genus used to make blue cheeses.Penicillium roquefortii is used in the manufacture of blue cheeses e.g. Roquefort, Gorgonzola, Stilton, etc.During the fermentation process the fungus spores are injected into the curd. By the way, the blue in the blue-cheese is caused by the pigment in the spores of the fungus.So, when you eat blue cheese you are consuming spores by the million.http://www.virtualmuseum.ca/Exhibitions/Mushroom/English/Lives/index.html

Yeast is the workhorseof eukaryotegenetics.

Yeasts are also essential to the productionof wine, beer and bread.

Some fungi are just really cool.