Kingdom FungiKingdom Fungi

• The characteristics The characteristics of fungiof fungi

• The evolution of The evolution of the fungithe fungi

• Fungal Fungal classificationclassification

• Fungal life stylesFungal life styles All photographsin this presentation © Pearson Education or Fred M. Rhoades

The Characteristics of FungiThe Characteristics of Fungi

• Fungi are NOT plants

• Hyphae = tubular units of construction

• Heterotrophic by absorption

• Reproduce by spores

• Ecologically pivotal roles

HyphaeHyphae

• Tubular

• Hard wall of chitin

• Crosswalls may form compartments (± cells)

• Multinucleate

• Grow at tips

Heterotrophic by AbsorptionHeterotrophic by Absorption• Fungi get carbon from organic sources

• Hyphal tips release enzymes

• Enzymatic breakdown of substrate

• Products diffuse back into hyphae

Product diffuses backinto hypha and is used

Nucleus hangs backand “directs”

Modifications of hyphaeModifications of hyphae

Fig 30.2 (don’t worry about the terms)

Hyphal growthHyphal growth• Hyphae grow from their tips

• Mycelium = extensive, feeding web of hyphae

• Mycelia are the ecologically active bodies of fungi

This wall is rigid Only the tip wall is plastic and stretches

Video of time lapse growth in a Zygomycote, Phycomyces

Reproduce by sporesReproduce by spores• Spores are reproductive cells

* Sexual* Asexual

• Formed:* Directly on hyphae* Inside sporangia* Fruiting bodies

Amanita fruiting body

Pilobolus sporangia

Penicillium hyphae

Hyphal growth from sporeHyphal growth from spore

mycelium

germinatingspore

• Mycelia have a huge surface area

Fig 31.1

myceliummycelium

fruiting bodiesfruiting bodies

both are composed of hyphae

Fungal EcologyFungal Ecology

• Saprobes* Decomposers* Mostly of plants, some animals

• Parasites* Harm host* Mostly on plants, some animals

• Mutualists* Lichens* Mycorrhizas* Others

Fig 28.8

Evolution of the fungiEvolution of the fungi

Classification & Phylogeny

motile spores

zygosporangia

ascibasidia

Fig 31.4

Chytridiomycota – “chytrids”Chytridiomycota – “chytrids”

• Simple fungi

• Produce motile spores

• Mostly saprobes and parasites in aquatic habitats

• Could just as well be Protists

Fig 31.5 Chytridium growing on spores

Zygomycota – “zygote fungi”Zygomycota – “zygote fungi”

• Sex - zygosporangia• Asex - common• Hyphae have no cross

walls• Grow rapidly

• Mycorrhizas

Fig 31.6 Rhizopus on strawberries

Fig 31.7 Life cycle of RhizopusYou are not responsible for this life cycleLife cycle is predominantly haploid

Asexual sporangium with spores inside

Sexual zygsporangium with one zygospore

Ascomycota – “sac fungi”Ascomycota – “sac fungi”

• Sex. – asci

• Asex. – common

• Cup fungi, morels, truffles

• Important plant parasites & saprobes

• Yeast - Saccharomyces

• Most lichensA cluster of asci with spores inside

Sac fungi Sac fungi diversitydiversity

• Note general comments about habitats and roles

• Enjoy looking at some amazing organisms

• This smaller-sized PPT file lacks diversity slides

Basidiomycota – “club fungi”Basidiomycota – “club fungi”

• Sex – basidia• Asex – not so common• Long-lived dikaryotic

mycelia• Rusts & smuts – primitive

plant parasites• Mushrooms, polypores,

puffballs• Enzymes decompose wood• Mycorrhizas

SEM of basidia and spores

Mushroom Mushroom Life CycleLife Cycle

Fig 31.12

Nuclear fusion in basidium

Meiosis

Hyphal fusion of haploid myceliahaploid

mycelium

young basidia - the only diploid cells

mycelium and fruiting body are dikaryotic

N 2N N+N

Club fungi Club fungi diversitydiversity

• Check out Taylor Lockwoods, “Treasures from the Kingdom Fungi”!

• This smaller-sized PPT file lacks diversity slides

A rust growing on a currant leaf

0.5 cm

• Yeasts

• Molds

• Mycorrhizas

• Lichens

YeastsYeasts

• Single celled fungi

• Adapted to liquids* Plant saps

* Water films

* Moist animal tissues

CandidaSaccharomyces

Schizosaccharomyces octospora – fermenter of Palm Wine

10 μm

MoldsMolds• Rapidly growth• Asexual spores• Many human importances

* Food spoilage* Food products* Antibiotics, etc.

Fig 31.21 Antibiotic activityNoble Rot - Botrytis

MycorrhizasMycorrhizas• “Fungus roots”

• Mutualism between:* Fungus (nutrient & water uptake for plant)

* Plant (carbohydrate for fungus)

• Several kinds* Zygomycota – hyphae invade root cells

* Ascomycota & Basidiomycota – hyphae invade root but don’t penetrate cells

• Extremely important ecological role of fungi!

““Ecto”mycorrhizasEcto”mycorrhizas

Russula mushroom mycorrhizas on Western Hemlock root

Fungal hyphae around root and between cells

Mycorrhiza cross sections

LichensLichens• “Mutualism” between

* Fungus – structure* Alga or

cyanobacterium – provides food

• Form a thallus* Foliose* Fruticose* Crustose

Fig 31.16

Lichen internal structureLichen internal structureFig 31.17

Lobaria

Lichens as biomonitorsLichens as biomonitors

• Thalli act like sponges

• Some species more sensitive

• Which species are present can indicate air quality

• (Most resistant species can also be analyzed for pollutants)

• Northwest Air Net Project* Species chart

* Table of sensitivities

Lichen Lichen diversitydiversity

• Check out my 3-D cryptogam site!

• More pictures of:* Lichens* Mushrooms* Bryophytes* Slime molds

• This smaller-sized PPT file lacks diversity slides