Session 7�

Fungi & Slime Molds (Unikonts)

Unikonts

Kingdom Fungi

• Club Fungi (Basidiomycota)
• Sac Fungi (Ascomycota)
• Sugar Molds (Mucuromycota)
• Chytrids (Chytridiomycota)

Kingdom Amoebozoa

• Slime Molds (Myxomycota)

Fungi/Animals

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Slime molds

Fungi

Animals

Archaea

Plants

Bacteria

Unikont Concepts & Terms

• Mycelium: mass of hyphae; fungus “body”
• Hypha: fungal filament, strands of fungus
• Coenocytic: cell with many nuclei; lack cross walls
• Siphonous: tube-like coenocytic cell
• Plasmodial: blob-like, coencytic mass of protoplasm
• Monokaryotic: cell with 1 nucleus
• Plasmogamy: fusion of cytoplasm between cells
• Dikaryotic: cell with 2 nuclei
• Karyogamy: fusion of nuclei

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2n

x400

Kingdom Fungi

Basidiomycota

Ascomycota

Zygomycota

Chytridiomycota

Kingdom Fungi

• Fundamental decomposers in nature
• Tremendously harmful and helpful
• Plant diseases, pneumonia, ringworm
• Alcohol production, penicillin, culinary delicacies
• Important symbiotic relationships
• Fungi have chitin in their cells walls

Chytrids

Mucuromycetes

Ascomycetes

Basidiomycetes

Animals

Slime molds

Use glycogen to store energy

Cell walls with chitin

Club Fungi�Basidiomycetes

• Mushrooms, toadstools, stinkhorns, puffballs, shelf fungi, rusts and smuts
• Major decomposers of plant litter
• Monokaryotic (n) & dikaryotic (n+n) phases
• Lifecycle is Haplontic!

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Basidiomycete Lifecycle

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Soil

Monokaryotic hyphae

Plasmogamy, without karyogamy

Dikaryotic hyphae

Fruiting body

is called a

Basidiocarp

Basidium is singular

Basidia is plural

Basidiomycota

gill

basidia

spores

basidiocarp

gill

basidia

spores

gill

Mushrooms, Toadstools, Shelf fungi�“Hymenomycetes” (Basidiomycetes)

• Mushrooms, coral-, tooth-, shelf- and bracket fungi

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• Basidiocarp is the mushroom
• Cap or pileus

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• Stalk or stipe

Hericium 

Clavulinopsis 

Amanita muscaria

Ganoderma 

Earth stars, Puffballs, Stinkhorns�“Gasteromycetes” (Basidomycetes)

• Puffballs, stinkhorns, bird’s-nest fungus, earthstars
• Basidiospores develop inside the Basidiocarp
• Basidiocarp is the globe-like structure

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Lycoperdon

Geastrum

Crucibulum

Phallus

Phallus indusiatus

Calvatia

spores

Rusts and Smuts�“Teliomycetes”

• Dikaryotic hyphae and basidia; no basidiocarp
• Tremendous agricultural damage
• White pine blister
• Cedar-apple rust
• Coffee rust
• Peanut rust
• Corn smut
• Wheat rust
• Extremely complex lifecycle
• Autoecious: lifecycle on 1 species
• Heteroecious: lifecycle on different species

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Sac Fungi�Ascomycetes

• Ascomycetes or sac fungi
• Molds, morels, truffles, Dutch Elm, powdery mildew
• Mycelium septate; septa perforated
• Monokaryotic (n) & dikaryotic (n+n)
• Ascocarp: large cup-shaped structure
• Ascus (2n): cell holding spores

Cordyceps

Xylaria

Morchella

Tuber

Peziza

Ascocarp

Ascus is singular

Asci is plural

spores

ascus

ascocarp

Sugar Molds �Mucuromycetes

• Sugar molds, mostly saprophytes, over 1,000 spp.
• Includes the glomeromycetes: arbuscular mycorrhizae
• Siphonous, haploid cells; no motile cells
• Zygote is called a zygo-sporangium (diploid)

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Rhizopus��

Chytrids

• Most ancient living fungi
• Mostly aquatic (nearly 800 spp.)
• Siphonous cells
• Motile cells aided by water
• Asexual zoospores
• Flagellated gametes
• Parasites and saprotrophs
• Plant pathogens: brown spot (corn), crown wart (alfalfa), black wart (potato)
• Parasites on other organisms, especially amphibians (chytridiomycosis)

410 million years old

Brown spot (corn)

Crown wart (alfalfa)

Black wart (potato)

Fungal Forms

• Yeasts
• Conidial fungi
• Mycorrhizae
• Lichens

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Artificial assemblage of fungi that possess a similar morphology and/or ecology

Yeasts

• Unicellular fungi
• Ascomycetes, Basidiomycetes, or Mucuromycetes
• Reproduce through budding (asexual)
• Sometimes sexual reproduction
• Commercially used as a source of ethanol and/or CO2
• Wine, beer and bread-making

Conidial Fungi

• Purely asexual fungi (15,000 spp.)
• Mostly ascomycetes, some basidiomycetes & mucuromycetes
• Once called Deuteromycetes or “Imperfect” Fungi
• Include Athlete's Foot and Penicillium

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(conidio)spores

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conidiophore

Mycorrhizae�“Fungus root”

• Mutualistic relationship between fungus & plant roots (or bryophyte thallus)
• 90% of all plants have mycorrhizal associations
• In these plants, few root-hairs develop; fungi act like root-hairs
• Fungus is much more efficient at absorption
• Endomycorrhizae: penetrate plant roots
• usually glomeromycete (Mucuromycota)
• most common (~80%)
• Ectomycorrhizae: surround root
• usually basidiomycete (some ascomycetes)
• e.g. Betulaceae, Fagaceae, Pinaceae

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410 million years old

Root cross-section

Lichens

• Fungus in symbiosis with an alga or cyanobacterium
• Mostly ascomycete body with basidiomycete “crust”
• Mutualistic relationship between these organisms
• Polyphyletic group
• Pioneer species
• Extremely widespread; indicator of air quality
• Forms:
• Crustose
• Foliose
• Fruticose

Myxomycota: slime molds

• Fungal-like protists: heterotrophic
• May represent ancestral protist with sexual reproduction
• Flagella in gametes
• Plasmodium: blob-like, coenocytic cell
• Sclerotium: dried, resting stage
• Sporangial stage

Growth of �slime mold

9am next morning

noon

3pm

Oat flake placed here

New plasmodial growth

Physarum sclerotium

Laboratory Slides

Coprinus basidiocarp (Basidiomycota)

• LABEL: Basidiocarp (Gill), Basidia, and Spores

Peziza apothecium (slide): Ascomycete

• LABEL: Ascocarp, Ascus, and Spores

Rhizopus conjugation (slide): Mucuromycete fungus

• LABEL: Hyphae, Zygo-sporangium

Peziza

Coprinus

spores

ascus

ascocarp

Peziza

gill of

basidiocarp

basidium

spores

x400

Coprinus

x100

Additional Slides

Gill of

Basidiocarp

Basidia

spores

x400

Coprinus

Peziza

x400

Fungal hyphae

Photosynthetic algae

Conidio-spores

Conidiophores

Lichen (x250)

Penicillium (x100)

Bread mold (x400)

Rhizopus

Yeast (x400)

Growth of Physarum

Asexual Reproduction: Rhizopus

Basidiospores

Ascospores

Peziza (Ascomycota)

Boletus (Basidiomycota)

Asexual Reproduction: Penicillium

Aspergillus (Deuteromycota)

Club Fungi (continued)

• Mycelium filamentous; cross walls are perforated
• Monokaryotic (n) & dikaryotic (n+n) phases
• Clamp connections
• Basidium (2n)

Basidiospores

Karyogamy

Meiosis

Basidium

gill of

mush-

room