What is the biggest organism ever?
Apatosaurus?
Blue whale?
Coast redwood?
None of the above – it’s a fungus
A single clone of the “honey mushroom”
Armillaria can cover more than 2,200 acres
(1,600 football fields)
Chapter 31
Fungi
Euglenozoa
Parabasala
Diplomonadida
Alveolata
Stramenopila
Radiolaria
Cercozoa
Fungi
Amoebozoa
Ancestral eukaryote
Figure 28.4
Plantae
Chlorophyta
Rhodophyta
Animalia
Choanoflagellates
Fungal Origins
Fungal Form and Function
Anatomy
Hyphae- thread-like
Hyphae and mycelium
Reproductive
structure or
fruiting body
filaments, one cell thick
See Fig. 31.2
Mycelium – interwoven mass of hyphae
Fungal Form and Function
Anatomy
Hyphae and mycelium
Mycelium
Hyphae
Fungal Form and Function
Anatomy
Septate hypha
Aseptate hypha,
a.k.a. coenocytic
See Fig. 31.3
Fungal Form and Function
Anatomy
Cell walls
contain
chitin
Fungal Form and Function
Immobile adults
Fungal Form and Function
Unlike plants
and animals,
no distinct
embryo is
formed
during early
development
Fungal Form and Function
Nutrition
Chemoheterotrophic
Fungi exude exoenzymes that break down
organic molecules that the fungi can absorb
and use as a supply of both energy and
carbon
Fungal Form and Function
Nutrition
Chemoheterotrophic
Saprobic – if they digest dead organisms and
waste products
Parasitic – if they digest live organisms
Mutualistically symbiotic – form associations
with other organisms for mutual benefit
Fungal Life Cycles
Three ploidy types
Haploid – most fungal hyphae and all spores
have haploid nuclei
Diploid – diploid nuclei are found transiently
during the sexual phase (if present)
Heterokaryon – unfused nuclei from different
parents occupying the same unit of hypha
Fungal Life Cycles
Reproduction
Asexual – default mode under stable
conditions; spores are produced
Fungal Life Cycles
Haploid (1n) spores
Heterokaryotic
stage
are produced
by
PLASMOGAMY
(fusion of cytoplasm)mitosis
Key
Haploid (n)
Heterokaryotic
Diploid (2n)
Spore-producing
structures
Spores
ASEXUAL
REPRODUCTION
GERMINATION
See Fig. 31.5
Mycelium
KARYOGAMY
Spores are genetically
(fusion of nuclei)
identical
to Zygote
original
SEXUAL
REPRODUCTION
mycelium
Spores disperse and
MEIOSIS
germinate
to
GERMINATION
produce Spore-producing
new
structures
Spores
myceliun
Fungal Form and Function
Reproduction
Asexual – default mode under stable
conditions; spores are produced
Sexual – usually only under stressful
conditions; spores are produced;
many mating types possible
(essentially like having many different
sexes or genders)
Sexual reproduction in fungi
+
fusion of compatible hyphae
(plasmogamy)
–
hyphae (n)
dispersal of spores
zygote (2n)
+
+
–
–
sexual spores (n)
meiosis of
“zygote-like”
structures
fused hyphae (n + n)
fusion of nuclei
(karyogamy)
zygotes (2n)
Sexual reproduction in fungi
Haploid spores may disperse long distances
away from the fruiting body
Fungal Life Cycles
Key
Fusion of
Haploid (n)
compatible
Heterokaryotic
hyphae
Diploid (2n)
(plasmogamy)
Heterokaryotic
stage
PLASMOGAMY
(fusion of cytoplasm)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
Spores
SEXUAL
REPRODUCTION
ASEXUAL
REPRODUCTION
Zygote
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Fungal Life Cycles
Key
Fusion of
Haploid (n)
compatible
Heterokaryotic
hyphae
Diploid (2n)
(plasmogamy)
Heterokaryotic
stage
PLASMOGAMY
(fusion of cytoplasm)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
…initiates a
Spores
heterokaryotic
ASEXUAL
phase REPRODUCTION
SEXUAL
REPRODUCTION
Zygote
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Fungal Life Cycles
Key
Fusion of
Haploid (n)
nuclei
Heterokaryotic
(karyogamy)
Heterokaryotic
stage
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
Spores
SEXUAL
REPRODUCTION
ASEXUAL
REPRODUCTION
Zygote
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Fungal Life Cycles
Key
Fusion of
Haploid (n)
nuclei
Heterokaryotic
(karyogamy)
Heterokaryotic
stage
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
…initiates
a
Spore-producing
zygoticstructures
phase
Spores
ASEXUAL
REPRODUCTION
SEXUAL
REPRODUCTION
Zygote
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Fungal Life Cycles
Key
Fusion of
Haploid (n)
nuclei
Heterokaryotic
(karyogamy)
Heterokaryotic
stage
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
…initiates
a
Spore-producing
zygoticstructures
phase
Spores
ASEXUAL
REPRODUCTION
…which is
perhaps best
describedGERMINATION
as
“zygote like”
SEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Zygote
Fungal Life Cycles
Key
Meiosis in
Haploid (n)
“zygote-like”
Heterokaryotic
cells produces
Diploid (2n) or cells
spores
that will
Spore-producing
produce
spores
structures
Spores
ASEXUAL
REPRODUCTION
Heterokaryotic
stage
PLASMOGAMY
(fusion of cytoplasm)
KARYOGAMY
(fusion of nuclei)
SEXUAL
REPRODUCTION
Zygote
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Fungal Life Cycles
Both asexual & sexual
reproduction produce
haploid spores
Key
Heterokaryotic
stage
Haploid (n)
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
Spores
SEXUAL
REPRODUCTION
ASEXUAL
REPRODUCTION
Zygote
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5
Arbuscular
mycorrhizal
fungi
Sac
fungi
Club
fungi
Glomeromycota
Ascomycota
Basidiomycota
Zygomycota
Over 100,000 species
described
Chytridiomycota
Fugal
Diversity
Zygote
fungi
Chytrids
Over 1000 additional
species described
each year
5 phyla
Loss of flagella*
See Fig. 31.9
*Flagella may have been lost multiple
times in the fist two lineages
Classification of Fungi
Phylum: Chytrids
Ancient group – diverged earliest from the
other fungi
Classification of Fungi
Phylum: Chytrids
Ancient group – diverged earliest from the
other fungi
Aquatic –
the only fungi with flagellated spores
(zoospores)
Sexual reproduction in a chytrid:
flagellated spores
spores
Classification of Fungi
Phylum: Chytrids
Ancient group – diverged earliest from the
other fungi
Aquatic –
the only fungi with flagellated spores
(zoospores)
Saprobic – majority
Parasitic – some
Classification of Fungi
Phylum: Zygomycetes = Zygote fungi
Sexual reproduction via zygosporangia
(resistant heterokaryons) that produce
genetically variable spores
Key
Black Bread Mold
Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Plasmogamy
Mating type (-)
Mating type (+)
Sexual reproduction
Zygosporangium
Karyogamy
Asexual
reproduction
See Fig. 31.12
Meiosis
Classification of Fungi
Phylum: Zygomycetes = Zygote fungi
Sexual reproduction via zygosporangia
(resistant heterokaryons) that produce
genetically variable spores
Asexual reproduction via sporangia that
produce spores
Key
Black Bread Mold
Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Plasmogamy
Mating type (-)
Mating type (+)
Sexual Reproduction
Zygosporangium
Karyogamy
Asexual
Reproduction
See Fig. 31.12
Meiosis
Classification of Fungi
Phylum: Zygomycetes = Zygote fungi
Sexual reproduction via zygosporangia
(resistant heterokaryons) that produce
genetically variable spores
Asexual reproduction via sporangia that
produce spores
Mostly saprobic decayers of organic matter,
e.g., soft fruit rot fungi and black bread
mold
Classification of Fungi
Phylum: Zygomycetes = Zygote fungi
Sexual reproduction via zygosporangia
(resistant heterokaryons) that produce
genetically variable spores
Asexual reproduction via sporangia that
produce spores
Mostly saprobic decayers of organic matter,
e.g., soft fruit rot fungi and black bread mold
Some parasites, e.g., single-celled
microsporidia
Classification of Fungi
Phylum: Glomeromycetes = Arbuscular
mycorrhizae
Associated with ~90% of plant species
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sexual reproduction via spores produced in
asci (sac-like cases)
Key
Neurospora
Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Conidia of mating type (-)
Asexual
Reproduction
Plasmogamy
Hyphae of mating type (+)
Karyogamy
Sexual Reproduction
Meiosis
See
Fig. 31.17
Ascocarp, ascus,
and ascospores
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sexual reproduction via spores produced in
asci (sac-like cases)
Asexual reproduction via naked spores
(conidia)
Key
Neurospora: an ascomycete
Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Conidia of mating type (-)
Asexual
Reproduction
Plasmogamy
Hyphae of mating type (+)
Karyogamy
Sexual Reproduction
Meiosis
See
Fig. 31.17
Ascocarp, ascus,
and ascospores
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Many saprobic species,
e.g., Scarlet cups
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Many parasites,
especially of plants, but
also of animals, e.g.,
Candida yeasts
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Many symbionts with
plants, e.g., truffles
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Morels – Delicacy or
deadly
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sources of many
interesting chemicals
E.g., Penicillium – the
source of penicillin
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sources of many
interesting chemicals
E.g., the source of LSD
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
The yeasts used to brew
beer…
Classification of Fungi
Phylum: Ascomycetes = Sac fungi
…and bake breads and
pizza crusts…
Classification of Fungi
…but the mushrooms
that top your pizza come
from a different phylum…
Classification of Fungi
Phylum: Basidiomycetes = Club fungi
Include:
common mushroom, puffballs,
stink horns, shelf fungi,
plant-parasitic smuts & rusts
Classification of Fungi
Phylum: Basidiomycetes = Club fungi
Include:
common mushroom, puffballs,
stink horns, shelf fungi,
plant-parasitic smuts & rusts
Sexual reproduction via club-shaped
reproductive structures, basidia,
containing basidiospores
A mushroom-forming
basidiomycete
See
Fig.
31.20
Plasmogamy
Basidiocarp
Mating type (-)
Mating type (+)
Sexual Reproduction
Basidia with
basidiospores
Karyogamy
Meiosis
Key
Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Classification of Fungi
Phylum: Basidiomycetes = Club fungi
Include:
common mushroom, puffballs,
stink horns, shelf fungi,
plant-parasitic smuts & rusts
Sexual reproduction via club-shaped
reproductive structures, basidia,
containing basidiospores
Asexual reproduction is uncommon
Phylum: Basidiomycetes = Club fungi
Fruiting bodies of the
“inky cap” mushroom
Phylum: Basidiomycetes = Club fungi
Basidia are generally found on the surface
of gills
gills
basidiospores
Phylum: Basidiomycetes = Club fungi
Basidia are generally found on the surface
of gills
Amanita
spore pattern
Phylum: Basidiomycetes = Club fungi
Giant puffball
Shelf fungi
Phylum: Basidiomycetes = Club fungi
Parasitic corn smut
Classification of Fungi
Deuteromycetes - Imperfect Fungi
Eclectic group of unclassified species
Classification of Fungi
Deuteromycetes - Imperfect Fungi
Eclectic group of unclassified species
Sexual structures unknown (i.e., no
flagellated spores, zygosporangia,
asci, or basidia), so these haven’t been
classified
Classification of Fungi
Deuteromycetes - Imperfect Fungi
Eclectic group of currently unclassified species
Sexual structures unknown (i.e., no
flagellated spores, zygosporangia,
asci, or basidia), so these haven’t been
classified
Includes many molds and mildews
(which demonstrates that
certain commonly recognized “groups”
are not good phylogenetic groups)
Functional Biology of Fungi
Molds
Many rapidly growing, asexually reproducing
fungi (mostly ascomycetes and basidiomycetes)
Ecosystems on Earth would collapse without the
molds and mildews (plus many bacteria) that
break down organic matter into inorganic nutrients
Functional Biology of Fungi
Yeasts
Many unicellular fungi that inhabit liquid or
moist surfaces and reproduce asexually
Occur in the Ascomycetes, Basidiomycetes &
Zygomycetes
Free-living, parasitic, and mutualistic symbiotic
forms exist
Functional Biology of Fungi
Mycorrhizae
Symbiotic associations with plants
(representatives known from all fungal phyla, not
just Glomeromycetes)
Functional Biology of Fungi
Lichens
Obligate symbiotic associations with algae or
cyanobacteria
Functional Biology of Fungi
Parasites
Chestnut blight
Ringworm
Functional Biology of Fungi
Toxin producers
Aflatoxin
Functional Biology of Fungi
Biotic control agents
The first antibiotic used by humans
Staphylococcus
Penicillium
Zone of
inhibited
growth
Functional Biology of Fungi
Biotic control agents
Used against termites, rice weevils, etc.
Functional Biology of Fungi
Interesting example…
of agriculture in insects
Leaf-cutter ants cut
and carry leaf fragments
to their nests where the
fragments are used to
farm fungi
Functional Biology of Fungi
Interesting example… of fungal cowboys
Some soil fungi
snare nematode
worms in hyphal
nooses and then
digest them
unlucky nematode
fungal hypha
Functional Biology of Fungi
Interesting example… of fungi & conservation
The golden toad became
extinct within the past 20
years, owing to anthropogenic
environmental deterioration,
which also facilitated
pathogenic chytrid fungi