1. We are
fun-guys!
Figure 31.1 Can you spot the largest organism in this forest?

2. There’s fungus among us!
Fungi are diverse and widespread
100,000 described species
Really as many as 1.5 MILLION?
Honey mushroom years old, 1,800 football fields (underground) or a yeast cell
Essential in ecosystem nutrient recycling
Mycology

3. There’s fungus among us!

4. Fungi are heterotrophs that feed by absorption
Despite their diversity, fungi share key traits, most importantly the way in which they derive nutrition

5. Nutrition and Ecology
Fungi are heterotrophs and absorb nutrients from outside of their body
Fungi use enzymes to break down a large variety of complex molecules into smaller organic compounds
The versatility of these enzymes contributes to fungi’s ecological success

6. Fungi exhibit diverse lifestyles:
Decomposers
Parasites
Mutualists

7. Animation: Fungal Reproduction and Nutrition
Body Structure
The most common body structures are multicellular filaments and single cells (yeasts)
Some species grow as either filaments or yeasts; others grow as both
Animation: Fungal Reproduction and Nutrition

8. Fungal Morphology
The morphology of multicellular fungi enhances their ability to absorb nutrients
Fungi consist of mycelia, networks of branched hyphae adapted for absorption
Most fungi have cell walls made of chitin

9. Reproductive structure
Fig. 31-2
Reproductive structure
Hyphae
Spore-producing
structures
Figure 31.2 Structure of a multicellular fungus
20 µm
Mycelium

10. Specialized Hyphae in Mycorrhizal Fungi
Some unique fungi have specialized hyphae called haustoria that allow them to penetrate the tissues of their host

11. ascomycete Fig. 31-4 Hyphae Nematode 25 µm
(a) Hyphae adapted for trapping and killing prey
Plant
cell
wall
Fungal hypha
Figure 31.4 Specialized hyphae
Plant cell
Plant cell
plasma
membrane
Haustorium
(b) Haustoria

12. Lasso sequence at 3 minutes
Fig. 31-4a
Hyphae
Nematode
25 µm
Figure 31.4 Specialized hyphae
(a) Hyphae adapted for trapping and killing prey
Lasso sequence at 3 minutes

13. Morgellons
Disease?
Figure 31.4 Specialized hyphae

14. Plant cell Fungal hypha wall Plant cell Plant cell plasma membrane
Fig. 31-4b
Plant
cell
wall
Fungal hypha
Plant cell
Figure 31.4 Specialized hyphae
Plant cell
plasma
membrane
Haustorium
(b) Haustoria

15. Mycorrhizae are mutually beneficial relationships between fungi and plant roots
Two types:

16. Mycorrhizae are mutually beneficial relationships between fungi and plant roots
Ectomycorrhizal fungi form sheaths of hyphae over a root and also grow into the extracellular spaces of the root cortex
Arbuscular mycorrhizal fungi extend hyphae through the cell walls of root cells and into tubes formed by invagination of the root cell membrane

17. Fungi produce spores through sexual or asexual life cycles
Fungi propagate themselves by producing vast numbers of spores, either sexually or asexually
Fungi have different types of life cycles

18. Haploid (n) Heterokaryotic (unfused nuclei from different parents)
Fig
Key
Haploid (n)
Heterokaryotic
(unfused nuclei from
different parents)
Diploid (2n)
Spore-producing
structures
Spores
ASEXUAL
REPRODUCTION
Mycelium
Figure 31.5 Generalized life cycle of fungi
GERMINATION

19. Haploid (n) Heterokaryotic stage Heterokaryotic (unfused nuclei from
Fig
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
(unfused nuclei from
different parents)
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
Zygote
SEXUAL
REPRODUCTION
Spores
ASEXUAL
REPRODUCTION
Mycelium
Figure 31.5 Generalized life cycle of fungi
GERMINATION

20. Haploid (n) Heterokaryotic stage Heterokaryotic (unfused nuclei from
Fig
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
(unfused nuclei from
different parents)
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
Zygote
SEXUAL
REPRODUCTION
Spores
ASEXUAL
REPRODUCTION
Mycelium
Figure 31.5 Generalized life cycle of fungi
MEIOSIS
GERMINATION
GERMINATION
Spores

21. Sexual Reproduction
Fungal nuclei are normally haploid, with the exception of transient diploid stages formed during the sexual life cycles
Sexual reproduction requires the fusion of hyphae from different mating types (“sexes”)
Fungi use sexual signaling molecules called pheromones to communicate their mating type (like many animals including primates!)

22. Plasmogamy is the union of two parent mycelia
In most fungi, the haploid nuclei from each parent do not fuse right away; they coexist in the mycelium, called a heterokaryon
The different nuclei may even swap DNA similar to “crossing over”.

23. Hours, days, or even centuries may pass before the occurrence of karyogamy, nuclear fusion (kary = nucleus)
During karyogamy, the haploid nuclei fuse, producing diploid cells
The diploid phase is short and undergoes meiosis (halving!), producing haploid spores

24. Asexual Reproduction
In addition to sexual reproduction, many fungi can reproduce asexually
Molds produce haploid spores by mitosis and form visible mycelia

25. Fig. 31-6
2.5 µm
Figure 31.6 Penicillium, a mold commonly encountered as a decomposer of food

26. Other fungi that can reproduce asexually are yeasts, which inhabit moist environments
Instead of producing spores, yeasts reproduce asexually by simple cell division and the pinching of “bud cells” from a parent cell

27. Sacchromyces cervisiae
Fig. 31-7
10 µm
Parent
cell
Figure 31.7 The yeast Saccharomyces cerevisiae in several stages of budding (SEM)
Bud
Sacchromyces cervisiae

28. Many molds and yeasts have no known sexual stage

29. The ancestor of fungi was an aquatic, single-celled, flagellated protist
Fungi and animals are more closely related to each other than they are to plants or other eukaryotes

30. The Origin of Fungi
Fungi, animals, and their protistan relatives form the opisthokonts clade

31. UNICELLULAR, FLAGELLATED Nucleariids ANCESTOR Opisthokonts Chytrids
Fig. 31-8
Animals (and their close
protistan relatives)
UNICELLULAR,
FLAGELLATED
ANCESTOR
Nucleariids
Opisthokonts
Chytrids
Figure 31.8 Fungi and their close relatives
Fungi
Other fungi

32. The oldest undisputed fossils of fungi are only about 460 million years old

33. The Move to Land
Fungi were among the earliest colonizers of land and probably formed mutualistic relationships with early land plants

34. Figure 31.11 Fungal diversity
Hyphae
25 µm
Chytrids (1,000 species)
Zygomycetes (1,000 species)
Fungal hypha
Glomeromycetes (160 species)
Ascomycetes (65,000 species)
Figure Fungal diversity
Basidiomycetes (30,000 species)

35. Chytrids (1,000 species) Hyphae 25 µm Fig. 31-11a
Figure Fungal diversity

36. They can be decomposers, parasites, or mutualists
Chytrids
Chytrids (phylum Chytridiomycota) are found in freshwater and terrestrial habitats
They can be decomposers, parasites, or mutualists
Molecular evidence supports the hypothesis that chytrids diverged early in fungal evolution
Chytrids are unique among fungi in having flagellated spores, called zoospores
Video: Allomyces Zoospore Release
Video: Phlyctochytrium Zoospore Release

37. Chytrids Zygomycetes Glomeromycetes Ascomycetes Basidiomycetes
Fig. 31-UN1
Chytrids
Zygomycetes
Glomeromycetes
Ascomycetes
Basidiomycetes

38. Fig
Figure Flagellated chytrid zoospore (TEM)
Flagellum
4 µm

39. Until recently, systematists thought that fungi lost flagella only once in their evolutionary history
Molecular data indicate that some “chytrids” are actually more closely related to another fungal group, the zygomycetes; chytrids are a paraphyletic group

40. Zygomycetes (1,000 species)
Fig b
Zygomycetes (1,000 species)
Figure Fungal diversity

41. Zygomycetes
The zygomycetes (phylum Zygomycota) exhibit great diversity of life histories
They include fast-growing molds, parasites, and commensal symbionts
The zygomycetes are named for their sexually produced zygosporangia
Zygosporangia, which are resistant to freezing and drying, can survive unfavorable conditions

42. Chytrids Zygomycetes Glomeromycetes Ascomycetes Basidiomycetes
Fig. 31-UN2
Chytrids
Zygomycetes
Glomeromycetes
Ascomycetes
Basidiomycetes

43. The life cycle of black bread mold (Rhizopus stolonifer) is fairly typical of the phylum

44. Some zygomycetes, such as Pilobolus, can actually “aim” their sporangia toward conditions associated with good food sources
Toward light = grass = cows = dispersal!
25m/sec = 1,million times its length/sec.
Fastest aerial acceleration in nature

45. Fig
Figure Pilobolus aiming its sporangia
Fungus Cannon!
0.5 mm

46. Glomeromycetes (160 species)
Fig c
Fungal hypha
Glomeromycetes (160 species)
Figure Fungal diversity

47. Glomeromycetes
The glomeromycetes (phylum Glomeromycota) were once considered zygomycetes
They are now classified in a separate clade
Glomeromycetes form arbuscular mycorrhizae

48. Chytrids Zygomycetes Glomeromycetes Ascomycetes Basidiomycetes
Fig. 31-UN3
Chytrids
Zygomycetes
Glomeromycetes
Ascomycetes
Basidiomycetes

49. Branched hyphae inside root cell (cleared)
Fig
Figure Arbuscular mycorrhizae
Branched hyphae inside root cell (cleared)
2.5 µm

50. Ascomycetes (65,000 species)
Fig d
Ascomycetes (65,000 species)
Figure Fungal diversity

51. Ascomycetes
Ascomycetes (phylum Ascomycota) live in marine, freshwater, and terrestrial habitats

52. Ascomycetes
Ascomycetes (phylum Ascomycota) live in marine, freshwater, and terrestrial habitats
The phylum is defined by production of sexual spores in saclike asci, usually contained in fruiting bodies called ascocarps

53. Ascomycetes
Ascomycetes (phylum Ascomycota) live in marine, freshwater, and terrestrial habitats
The phylum is defined by production of sexual spores in saclike asci, usually contained in fruiting bodies called ascocarps
Ascomycetes are commonly called sac fungi
Ascomycetes vary in size and complexity from unicellular yeasts to elaborate cup fungi and morels

54. Ascomycetes include plant pathogens, decomposers, and symbionts
Ascomycetes reproduce asexually by enormous numbers of asexual spores called conidia

55. Ascomycetes include plant pathogens, decomposers, and symbionts
Ascomycetes reproduce asexually by enormous numbers of asexual spores called conidia
Conidia are not formed inside sporangia; they are produced asexually at the tips of specialized hyphae called conidiophores

56. Chytrids Zygomycetes Glomeromycetes Ascomycetes Basidiomycetes
Fig. 31-UN4
Chytrids
Zygomycetes
Glomeromycetes
Ascomycetes
Basidiomycetes

57. Ascomycetes: The Good the Bad and the Ugly
Part I: The Good
Morchella esculenta,
the tasty morel
Tuber melanosporum, a truffle
Figure Ascomycetes (sac fungi)

58. Morchella esculenta, the tasty morel Fig. 31-16a
Figure Ascomycetes (sac fungi)

59. ca. $600/lb Tuber melanosporum, a truffle Fig. 31-16b
Figure Ascomycetes (sac fungi)
The Associate Press reported that a real estate investor and his wife from Hong Kong have paid €125,000 ($160,406 USD) for a gigantic Italian White Alba truffle which is reportedly the world’s most expensive ever. The most expensive truffle weighs in 1.51 kilograms (3.3 lbs).

60. Alexander Fleming’s “moldy plate” (1928)
Fig
Alexander Fleming’s “moldy plate” (1928)
Staphylococcus
Penicillium
Zone of
inhibited
growth
Figure Fungal production of an antibiotic

61. Sacchromyces cervisiae
Fig. 31-7
10 µm
Parent
cell
Figure 31.7 The yeast Saccharomyces cerevisiae in several stages of budding (SEM)
Bud
Sacchromyces cervisiae

62. 6,000 years old Starter = old dough
Figure Ascomycetes (sac fungi)
A seal around 4,000 years old is a Sumerian "Hymn to Ninkasi", the goddess of brewing. This "hymn" is also a recipe for making beer.

63. Ascomycetes Part II: The Bad
Mycoses - Ringworm, indoor molds (sick buildings), athelete’s foot, Candida (diaper rash and worse)Candida albicans
Fusarium (grains; Jurgenson research)
Cryptococcus (pigeon poop)
Ergot!

64. Ascomycota: Claviceps (“ergot”)
Parasitic on grains
of grasses:
(rye, barley, wheat)

65. Ascomycota: Claviceps (“ergot”)
Parasitic on grains
of grasses:
(rye, barley, wheat)
infects flowers and replaces mature grain with sclerotia
sclerotia

66. Ascomycota: Claviceps (“ergot”)
Parasitic on grains
of grasses:
(rye, barley, wheat)
infects flowers and replaces mature grain with sclerotia
hard sclerotia allow the fungus to survive freezing and desiccation
sclerotia

67. Ascomycota: Claviceps (“ergot”)
Parasitic on grains
of grasses:
(rye, barley, wheat)
infects flowers and replaces mature grain with sclerotia
hard sclerotia allow the fungus to survive freezing and desiccation
“argot” = spur
sclerotia

68. Alkaloids produced by Claviceps purpurea:
Ergotamine - vasoconstrictor

69. Alkaloids produced by Claviceps purpurea:
Ergotamine - vasoconstrictor
Ergonovine - spontaneous abortions

70. Alkaloids produced by Claviceps purpurea:
Ergotamine - vasoconstrictor
Ergonovine - spontaneous abortions
Ergine - gastrointestinal toxin, seizures, formication

71. Alkaloids produced by Claviceps purpurea:
Ergotamine - vasoconstrictor
Ergonovine - spontaneous abortions
Ergine - gastrointestinal toxin, seizures, formication
Lysergic Acid Hydroxyethylamide - hallucinations

72. Ascomycota: Claviceps (“ergot”)
“Holy Fire” (Ignis Sacer)

73. Ascomycota: Claviceps (“ergot”)
“Holy Fire” (Ignis Sacer)
,000 died in France

74. Ascomycota: Claviceps (“ergot”)
“Holy Fire” (Ignis Sacer)
,000 died in France
“St. Anthony’s Fire”

75. Ascomycota: Claviceps (“ergot”)
“Holy Fire” (Ignis Sacer)
,000 died in France
“St. Anthony’s Fire”
Salem Witch Trials

76. Ascomycota: Claviceps (“ergot”)
“Holy Fire” (Ignis Sacer)
,000 died in France
“St. Anthony’s Fire”
Salem Witch Trials
in Sologne, France

77. Ascomycota: Claviceps (“ergot”)
“Holy Fire” (Ignis Sacer)
,000 died in France
“St. Anthony’s Fire”
Salem Witch Trials
in Sologne, France
Lysergic acid diethylamide (LSD-25: Albert Hofmann)

78. “Holy Fire” (Ignis Sacer)
,000 died in France
“St. Anthony’s Fire”
Salem Witch Trials
in Sologne, France
Lysergic acid diethylamide (LSD-25: Albert Hofmann)
Pont-St. Esprit, France

81. Cordyceps fly Ascomycetes Part II: The Ugly Bullet ants in trouble
Figure 31.4 Specialized hyphae
moth

83. Geomyces destructans
White nose Syndrome
Causes early arousal?
Up to 97% mortality
Now in Missouri

84. Conidiophores w/ conidia
colony
conidia
Conidiophores w/ conidia

85. Basidiomycetes (30,000 species)
Fig e
Basidiomycetes (30,000 species)
Figure Fungal diversity

86. Basidiomycetes
Basidomycetes (phylum Basidiomycota) include mushrooms, puffballs, and shelf fungi, mutualists, and plant parasites
The phylum is defined by a clublike structure called a basidium, a transient diploid stage in the life cycle
The basidiomycetes are also called club fungi

87. Chytrids Zygomycetes Glomeromycetes Ascomycetes Basidiomycetes
Fig. 31-UN5
Chytrids
Zygomycetes
Glomeromycetes
Ascomycetes
Basidiomycetes

88. Fig
Maiden veil fungus
(Dictyphora), a
fungus with an
odor like rotting
meat
Puffballs emitting
spores
Shelf fungi, important
decomposers of wood
Figure Basidiomycetes (club fungi)

89. (eat slime pass spores)
Fig a
Maiden veil fungus
(Dictyphora), a
fungus with an odor like rotting meat
Figure Basidiomycetes (club fungi)
Fly dispersed
(eat slime pass spores)

90. Puffballs emitting 70 trillion! spores Fig. 31-18b
Figure Basidiomycetes (club fungi)
70 trillion!

91. Shelf fungi, important decomposers of wood Fig. 31-18c
Figure Basidiomycetes (club fungi)

92. The life cycle of a basidiomycete usually includes a long-lived dikaryotic mycelium
In response to environmental stimuli, the mycelium reproduces sexually by producing elaborate fruiting bodies call basidiocarps
Mushrooms are examples of basidiocarps
The numerous basidia in a basidiocarp are sources of sexual spores called basidiospores

93. Dikaryotic mycelium Haploid mycelia Mating type (–) Mating type (+)
Fig
Dikaryotic mycelium
Haploid mycelia
PLASMOGAMY
Mating
type (–)
Mating
type (+)
SEXUAL
REPRODUCTION
Figure The life cycle of a mushroom-forming basidiomycete
Key
Haploid (n)
Dikaryotic (n +n)
Diploid (2n)

94. Dikaryotic mycelium Haploid mycelia Mating type (–) Mating type (+)
Fig
Dikaryotic mycelium
Haploid mycelia
PLASMOGAMY
Mating
type (–)
Mating
type (+)
Gills lined
with basidia
SEXUAL
REPRODUCTION
Basidiocarp
(n+n)
Basidia
(n+n)
Figure The life cycle of a mushroom-forming basidiomycete
Key
Haploid (n)
Dikaryotic (n +n)
Diploid (2n)

95. Dikaryotic mycelium Haploid mycelia Mating type (–) Mating type (+)
Fig
Dikaryotic mycelium
Haploid mycelia
PLASMOGAMY
Mating
type (–)
Mating
type (+)
Gills lined
with basidia
SEXUAL
REPRODUCTION
Basidiocarp
(n+n)
Basidia
(n+n)
Figure The life cycle of a mushroom-forming basidiomycete
KARYOGAMY
Key
Haploid (n)
Dikaryotic (n +n)
Diploid
nuclei
Diploid (2n)

96. Dikaryotic mycelium Haploid mycelia Mating type (–) Mating type (+)
Fig
Dikaryotic mycelium
Haploid mycelia
PLASMOGAMY
Mating
type (–)
Mating
type (+)
Gills lined
with basidia
Haploid mycelia
SEXUAL
REPRODUCTION
Basidiocarp
(n+n)
Dispersal and
germination
Basidiospores
(n)
Basidium with
four basidiospores
Basidia
(n+n)
Basidium
Figure The life cycle of a mushroom-forming basidiomycete
Basidium containing
four haploid nuclei
KARYOGAMY
MEIOSIS
Key
Haploid (n)
Dikaryotic (n +n)
Diploid
nuclei
1 µm
Basidiospore
Diploid (2n)

97. Fig
Figure A fairy ring

98. Concept 31.5: Fungi play key roles in nutrient cycling, ecological interactions, and human welfare
Fungi interact with other organisms in many ways

99. Fungi as Decomposers
Fungi are efficient decomposers
They perform essential recycling of chemical elements between the living and nonliving world

100. Fungi as Mutualists
Fungi form mutualistic relationships with plants, algae, cyanobacteria, and animals
All of these relationships have profound ecological effects

101. Fungus-Plant Mutualisms
Mycorrhizae are enormously important in natural ecosystems and agriculture
Plants harbor harmless symbiotic endophytes that live inside leaves or other plant parts
Endophytes make toxins that deter herbivores and defend against pathogens

102. 30 15 20 10 10 5 E–P+ E+P+ E–P+ E+P+ RESULTS
Fig
RESULTS
Endophyte not present; pathogen present (E–P+)
Both endophyte and pathogen present (E+P+) 30 15 20 10
Leaf mortality (%)
Leaf area damaged (%)
Figure Do endophytes benefit a woody plant? 10 5
E–P+
E+P+
E–P+
E+P+

103. Fungus-Animal Symbioses
Some fungi share their digestive services with animals
These fungi help break down plant material in the guts of cows and other grazing mammals
Many species of ants and termites use the digestive power of fungi by raising them in “farms”

104. Fig
Figure Fungus-gardening insects
For the Discovery Video Leafcutter Ants, go to Animation and Video Files.

105. Figure 31.22 Fungus-gardening insects
For the Discovery Video Leafcutter Ants, go to Animation and Video Files.

106. Lichens
A lichen is a symbiotic association between a photosynthetic microorganism and a fungus in which millions of photosynthetic cells are held in a mass of fungal hyphae

107. Crustose (encrusting) lichens A foliose (leaflike) lichen
Fig
 Crustose
(encrusting)
lichens
A fruticose (shrublike) lichen
 A foliose
(leaflike)
lichen
Figure Variation in lichen growth forms

108. A fruticose (shrublike) lichen
Fig a
A fruticose (shrublike) lichen
Figure Variation in lichen growth forms

109. Crustose (encrusting) lichens Fig. 31-23b
Figure Variation in lichen growth forms

110. A foliose (leaflike) lichen Fig. 31-23c
Figure Variation in lichen growth forms

111. The fungal component of a lichen is most often an ascomycete
Algae or cyanobacteria occupy an inner layer below the lichen surface

112. Ascocarp of fungus Soredia Fungal hyphae Algal layer Algal cell
Fig
Ascocarp of fungus
Soredia
Fungal
hyphae
Algal
layer
Figure Anatomy of an ascomycete lichen (colorized SEM)
Algal cell
20 µm
Fungal hyphae

113. The algae provide carbon compounds, cyanobacteria provide organic nitrogen, and fungi provide the environment for growth
The fungi of lichens can reproduce sexually and asexually
Asexual reproduction is by fragmentation or the formation of soredia, small clusters of hyphae with embedded algae

114. Lichens are important pioneers on new rock and soil surfaces
Lichens are sensitive to pollution, and their death can be a warning that air quality is deteriorating

115. Fungi as Pathogens
About 30% of known fungal species are parasites or pathogens, mostly on or in plants
Some fungi that attack food crops are toxic to humans
Animals are much less susceptible to parasitic fungi than are plants
The general term for a fungal infection in animals is mycosis

116. Practical Uses of Fungi
Humans eat many fungi and use others to make cheeses, alcoholic beverages, and bread
Some fungi are used to produce antibiotics for the treatment of bacterial infections, for example the ascomycete Penicillium
Genetic research on fungi is leading to applications in biotechnology
For example, insulin-like growth factor can be produced in the fungus Saccharomyces cerevisiae

117. Fig. 31-UN6

118. Fig. 31-UN6a

119. Fig. 31-UN6b

120. Fig. 31-UN6c

121. Fig. 31-UN6d

122. Fig. 31-UN6e