Kingdom Fungi

All photographsin this presentation © Pearson Education or Fred M. Rhoades

The Characteristics of Fungi

• Fungi are NOT plants

• Hyphae = tubular units of construction

• Heterotrophic by absorption

• Reproduce by spores

• Ecologically pivotal roles

Hyphae

• Tubular

• Hard wall of chitin

• Crosswalls may form compartments (± cells)

• Multinucleate

• Grow at tips

Heterotrophic 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 hyphaeFig 30.2 (don’t worry about the terms)

Hyphal 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

Fungal Growth Video http://www.youtube.com/watch?v=puDkLFcCZyI

Reproduce 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 spore

mycelium

germinatingspore

• Mycelia have a huge surface area

Fig 31.1

myceliummycelium

fruiting bodiesfruiting bodies

both are composed of hyphae

Fungal 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”

• 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”

• 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

Ascomycetes – “sac fungi”

• Sex. – asci• Asex. – common• Cup fungi, morels,

truffles• Important plant

parasites & saprobes• Yeast -

Saccharomyces• Most lichens A cluster of asci with spores inside

Sac fungi diversity

• Note general comments about habitats and roles

• Enjoy looking at some amazing organisms

• This smaller-sized PPT file lacks diversity slides

Basidiomycetes – “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 Life 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 diversity

• 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

Yeasts

• Single celled fungi• Adapted to liquids

– Plant saps– Water films– Moist animal tissues

CandidaSaccharomyces

Schizosaccharomyces octospora – fermenter of Palm Wine

10 μm

Molds Zygomycetes

• Rapidly growth• Asexual spores• Many human

importances– Food spoilage– Food products– Antibiotics, etc.

Fig 31.21 Antibiotic activityNoble Rot - Botrytis

Mycorrhizas• “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”mycorrhizas

Russula mushroom mycorrhizas on Western Hemlock root

Fungal hyphae around root and between cells

Mycorrhiza cross sections

Lichens• “Mutualism”

between– Fungus – structure– Alga or

cyanobacterium – provides food

• Form a thallus

Fig 31.16

Lichen internal structureFig 31.17

Lobaria

Lichens 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)

Lichen diversity