1. Kingdom Fungi
Chapter 21

2. LEARNING OBJECTIVE 1
Describe the distinguishing characteristics of the kingdom Fungi

3. Fungi Eukaryotes that lack chlorophyll and are heterotrophic
Absorb predigested food through the cell wall and plasma membrane

4. WAYS FUNGI AFFECTS LIVING THINGS
Cause food spoilage
Make food products better
Provides a food source
Provide medicine
Cause plant disease
Damage property
Cause disease

5. Examples of foods made possible by fungi
Yeast
Beer and Wine
Bread
Mushrooms
White button, crimini,portabella
Truffles, chanterelles
Mycoprotein
(food additive like tofu)
Cheese
Rennin,
blue cheese
Soy sauce
Tempeh
Citric acid
(soft drinks)

6. Evolutionary History of Fungi
Fungi appeared around 1.5 billion years ago.
Earliest fungi were aquatic.
Fungi are more closely related to animals than plants.
Fungi probably evolved from a flagellated protist.

7. KEY TERMS
CHITIN
A nitrogen-containing polysaccharide that forms cell walls of many fungi
HYPHA
One of the threadlike filaments composing the mycelium of a fungus

8. KEY TERMS MYCELIUM Other fungi (yeasts) are unicellular
Vegetative (nonreproductive) body of most fungi, consisting of a branched network of hyphae
Other fungi (yeasts) are unicellular

9. Filamentous Fungi

10. growing on agar in a culture dish. In nature, fungal
Hyphae
(c)
(d)
(e)
(a) A fungal mycelium
growing on agar in a culture dish. In
nature, fungal
mycelia are rarely
so symmetrical.
(b) Electron micrograph of a mycelium.
(c) A hypha divided into cells by
septa; each cell is monokaryotic.
In some fungi the septa are
perforated (as shown).
(d) A septate hypha in which
each cell is dikaryotic (has
two nuclei).
(e) A coenocytic hypha.
Figure 21.1: Filamentous fungi.
Fig. 21-1, p. 407

11. LEARNING OBJECTIVE 2
Explain the fate of a fungal spore that lands on an appropriate food source

12. KEY TERMS
SPORE
A reproductive cell that gives rise to individual offspring in fungi and certain other organisms

13. Spores Fungi reproduce by spores
May be produced sexually or asexually
When a fungal spore comes into contact with an appropriate food source, the spore germinates and begins to grow a mycelium

14. Germination: Spore to Mycelium

15. Spore Hypha Mycelium Fig. 21-2, p. 407
Figure 21.2: Germination of a spore to form a mycelium.
Mycelium
Fig. 21-2, p. 407

16. LEARNING OBJECTIVE 3
List distinguishing characteristics and give examples of each of the following fungal groups: chytridiomycetes, zygomycetes, glomeromycetes, ascomycetes, and basidiomycetes

17. Major Phyla of Fungi

18. Evolution of ascospores Common flagellated ancestor
Zygomycetes
Glomeromycetes
Basidiomycetes
Ascomycetes
Chytrids
Evolution of
ascospores
Evolution of
basidiospores
Evolution of
dikaryotic stage
Figure 21.3: Major phyla of fungi.
This cladogram shows evolutionary relationships among the fungi, based on comparisons of DNA sequence data for many species. The chytrids branched off first during fungal evolution.
Loss of flagellum
Common
flagellated
ancestor
Fig. 21-3, p. 408

19. KEY TERMS CHYTRID (chytridiomycetes)
A fungus characterized by production of flagellated cells at some stage in its life history
A parasitic chytrid is partly responsible for declining amphibian populations

20. A Chytrid

21. KEY TERMS
ZYGOMYCETE
A fungus characterized by production of nonmotile, asexual spores and sexual zygospores
Black bread mold is a zygomycete

22. A Zygomycete

23. Life Cycle: Black Bread Mold

24. In asexual reproduction, certain hyphae form
Spore germinates 1a
In asexual reproduction,
certain hyphae form
sporangia in which clusters
of black, asexual, haploid
spores develop. When
released, they give rise
to new hyphae.
ASEXUAL
REPRODUCTION
(by spores)
Haploid (n) 7
Spores germinate and
produce haploid mycelia.
Sporangia
Spores + -
Sporangium containing
spores produced
by mitosis
SEXUAL REPRODUCTION
HAPLOID (n)
STAGE 1b
Hyphae of (+)
and (-) mating types grow
toward one another. + - 6
Meiosis occurs and zygospore germinates;
hypha develops
sporangium at
its tip.
Figure 21.6: The life cycle of the black bread mold.
(Top) Asexual reproduction involves the formation of haploid spores. (Bottom) Sexual reproduction in the black bread mold (Rhizopus nigricans) takes place only between genetically distinct mating types, which are designated + and −.
Germination of
zygospore
DIPLOID (2n)
STAGE +
Mature zygospore
within zygosporangium
Gametangia -
When (+) and (-)
hyphae meet,
they form
gametangia. 2
Meiosis
Plasmogamy 5
Zygospore develops
from zygote; it is
encased by thick-walled,
black zygosporangium.
Plasmogamy occurs
as gametangia fuse.
Karyogamy 3 4
Karyogamy occurs with nuclei fusing to form diploid zygote.
Fig. 21-6, p. 410

25. Microsporidium Infection

26. Microsporidian cell Polar tube Host cell 1 Spore of microsporidium
Figure 21.7: Infection by a microsporidium. 1
Spore of
microsporidium
has coiled
polar tube. 2
Spore ejects
its polar tube
and penetrates
host cell. 3
Infective
cytoplasm is
injected into
host cell.
Fig. 21-7, p. 411

27. 1. Spore of microsporidium has coiled
Microsporidian cell
Polar tube
1. Spore of microsporidium has coiled
polar tube.
2. Spore ejects
its polar tube and penetrates host cell.
3. Infective cytoplasm is injected into host cell.
Host cell
Figure 26.10: Infection by microsporidium.
Stepped Art
Fig. 21-7, p. 411

28. Animation: Zygomycete Life Cycle
CLICK TO PLAY

29. KEY TERMS GLOMEROMYCETE
A fungus that forms a distinctive branching form (arbuscular mycorrhizae) of endomycorrhizae with roots of most trees and herbaceous plants

30. Glomeromycetes

31. Cells of root cortex Root epidermis Soil Vesicle Root hair Arbuscule
Spore
Figure 21.8: Glomeromycetes.
These fungi form arbuscular mycorrhizae. Note how the mycelium has grown into the root, and its hyphae branch between the cells of the root. Hyphae have penetrated through the cell walls of two root cells and have branched extensively to form arbuscules. The tip of one hypha between root cells has enlarged and serves as a vesicle that stores food. The tip of a hypha in the soil has enlarged, forming a spore. The spaces between the root cells have been magnified.
Cortex
cell
Hyphae of fungus
Fig. 21-8, p. 412

32. KEY TERMS
ASCOMYCETE
A fungus characterized by production of nonmotile, asexual conidia and sexual ascospores
Ascomycetes include yeasts, cup fungi, morels, truffles, pink and green molds

33. Conidia

34. Conidia Fig. 21-9, p. 412 Figure 21.9: Conidia.
Conidia are asexual reproductive cells produced by ascomycetes and a few basidiomycetes. Shown is an electron micrograph of Penicillium conidiophores, which resemble paintbrushes. Note the conidia pinching off the tips of the “brushes.”
Fig. 21-9, p. 412

35. Life Cycle: Ascomycetes

36. In asexual reproduction, hyphae produce haploid conidia. Germinating
conidium 9
When
released,
ascospores
germinate and
form new
haploid
mycelia.
ASEXUAL
REPRODUCTION
(by spores)
Conidiophore
Haploid (n) 1
Haploid mycelia
of opposite mating
types both produce
coenocytic sexual
hyphae.
(–) mating type 8
Each nucleus
becomes
incorporated
into an
ascospore.
(–) mating type
Plasmogamy 2
Plasmogamy
occurs as hyphae
of the two mating
types fuse and
nuclei are exchanged.
Nuclei
migrate.
Mature ascus has eight
haploid ascospores.
SEXUAL REPRODUCTION
HAPLOID (n)
STAGE 3
Dikaryotic
hyphae form
and produce
asci.
Second meiotic
division
DIKARYOTIC
STAGE
(n + n)
Mitosis produces
eight haploid nuclei. 7
Figure 21.10: The life cycle of an ascomycete.
(Top) Asexual reproduction involves the formation of haploid conidia. (Bottom) Sexual reproduction involves the fusion of two haploid hyphae to form a dikaryotic (n + n) structure. Asci form from this structure; in each ascus the n + n nuclei fuse, followed by meiosis and mitosis to produce eight ascospores. The asci form the inner layer of a fruiting body known as an ascocarp.
First meiotic
division
DIPLOID (2n)
STAGE
Developing
ascus with
n + n nuclei 6
Meiosis occurs,
forming four
haploid nuclei.
Zygote
Hyphae form
an ascocarp.
Nuclei fuse 4
Meiosis
Ascocarp
Karyogamy occurs in
each ascus. Two haploid nuclei fuse, forming a diploid zygote nucleus. 5
Karyogamy
Mycelium
Fig , p. 414

37. Sexual Reproduction in Ascomycetes

38. Penicillium. The mold Penicillium produces penicillin, which inhibits the growth of Gram-positive bacteria.

39. Penicillium
WWI, bacterial infections killed more soldiers than bullets did directly.
1928 Dr. Fleming working at St. Mary’s Hospital in London noticed that mold growing on staph bacterial culture plates had killed the pathogen
zone of dead bacteria
The action of penicillin is seen in Figure A. This shows an 'overlay plate', in which a central colony of the fungus Penicillium notatum was allowed to grow on agar for 5-6 days, then the plate was overlaid with a thin film of molten agar containing cells of the yellow bacterium, Micrococcus luteus. The production of penicillin by the fungus has created a zone of growth inhibition of the bacterium. This demonstration parallels what Alexander Fleming would have observed originally, although he saw inhibition and cellular lysis of the bacterium Staphylococcus aureus.
Figure B shows the typical asexual sporing structures of a species of Penicillium. The spores are produced in chains from flask-shaped cells (phialides) which are found at the tips of a brush-like aerial structure.
B&W is an actual photograph of Fleming’s dish (note clear lysed bacterial cells in zone around mold)

40. Penicillin kills bacteria by interfering with their ability to synthesize cell wall.
In this sequence, Escherichia coli were incubated in penicillin for 30 minutes. The bacteria lengthen, but cannot divide. Eventually the weak cell wall ruptures (last panel).
In this sequence, Escherichia coli were incubated in
penicillin for 30 minutes. The bacteria lengthen, but cannot divide.
Eventually the weak cell wall ruptures (last panel).

41. Animations Mode of action of Pennicillin:
Development of Antibiotic resistance:

42. KEY TERMS BASIDIOMYCETE
A fungus characterized by production of sexual basidiospores
Basidiomycetes include mushrooms, puffballs, rusts, smuts

43. Basidiomycete Fruiting Bodies

45. Sexual Reproduction in Basidiomycetes

46. Cap Gill, bearing basidia Basidiospore Basidium Gills Button stage
Fruiting body
(Basidiocarp)
Stalk
Base
Figure 21.13: Sexual reproduction in the basidiomycetes.
Mycelium
(a) Compacted hyphae form the basidiocarp commonly called a mushroom. Numerous basidia are borne on the gills.
(b) Each basidium produces four basidiospores, which are attached to the basidium.
Fig , p. 417

47. Life Cycle: Basidiomycetes

48. HAPLOID (n) STAGE DIKARYOTIC STAGE (n + n) DIPLOID (2n) STAGE1
Basidiospores germinate
and form primary mycelia.
Basidiospores
released 2
Plasmogamy occurs
with the fusion of two
(n) hyphae of
different mating
types.
Basidiospores
forming
Plasmogamy
HAPLOID (n)
STAGE 3
Fast-growing secondary
mycelium is produced,
composed of dikaryotic
(n + n) hyphae.
Second meiotic
division
DIKARYOTIC
STAGE
(n + n)
First meiotic
division
DIPLOID
(2n)
STAGE 4
Basidiocarps
periodically
develop from
secondary
mycelium.
Figure 21.14: Life cycle of a typical basidiomycete.
Note the dikaryotic stage and the separation of plasmogamy and karyogamy. Asexual reproduction is uncommon in this group. 6
Meoisis occurs,
producing four
haploid nuclei
that become
basidiospores.
Zygote nucleus
Meiosis
Karyogamy
Gills
Basidiocarp 5
Basidia form along gills of
basidiocarps. In each
basidium karyogamy
occurs, producing a
zygote nucleus.
Secondary
mycelium
Fig , p. 418

49. Animation: Club Fungus Life Cycle
CLICK TO PLAY

50. LEARNING OBJECTIVE 4
Explain the ecological significance of fungi as decomposers

51. Decomposers Most fungi are decomposers
Break down organic compounds in dead organisms, leaves, garbage, and wastes into simpler materials that can be recycled
Without continuous decomposition
Essential minerals would be unavailable for use by new generations of organisms
Life would cease

52. LEARNING OBJECTIVE 5
Describe the important ecological role of mycorrhizae

53. Mycorrhizae
Mutualistic relationships between fungi and roots of plants
Fungus supplies minerals to plant
Plant secretes organic compounds needed by fungus

54. KEY TERMS ENDOMYCORRHIZAL FUNGI ECTOMYCORRHIZAL FUNGI
Fungi that form mycorrhizae that extend into plant roots
ECTOMYCORRHIZAL FUNGI
Fungi that form mycorrhizae consisting of a dense sheath over the root’s surface

55. Experiment: Mycorrhizae

56. Mycorrhizae “myco” = fungus and “rhiza” = root
Symbiotic association between plant roots and fungi
Several different types of association (defined by structure of fungus:plant interface)
Types of mycorrhizae are defined by interface structures
VAM - hyphae and arbuscules of an endomycorrhizal fungus in Asarum (wild ginger) (see Fig 15 in Brundrett & Kendrick 1988 Can. J. Bot. 66: 1153)
Colonization of a root by an endomycorrhizal fungus. Note hyphae, arbuscules and vesicles. (Fig. 21 in Brundrett et al Can. J. Bot. 63: 184-)
ECTO - page dichotomous ectomycorrhizas (upper) and mycelial strands (lower) of Amanita muscaria on Pinus strobus.online Pictorial Supplement to The Fifth Kingdom - Chapter 17 Mycorrhizae - mutualistic plant-fungus symbioses. Photo posted by Bryce Kendrick and Mycologue Publications. Other acknowledgements

57. Mycorrhizae Endomycorrhizae:
Vesicular-Arbuscular Mycorrhizae (VAM, AM).
Most common type of mycorrhizae (textbook: ~240,000 plant species, ~6000 fungal species; Trappe, 1987: ~2/3 of all plant species).
Fungi = Zygomycetes, many kinds of plants (bryophytes, ferns, gymnosperms, angiosperms) Important step in evolution of land plants?
VAM Fungi haven’t been cultured, can’t degrade complex organic matter, rely on simple C compounds from plants. Survive as chlamydospores in soil untilinfection. Plants can usually live without association, but not as well.
Important for P uptake, recently shown to transfer organic N to plant.
Vesicles: survival structures within plant. Fungus can grow along the inside of the root as root grows.
Arbuscules: highly branched hyphae - transfer nutrients when arbuscules are digested by plant.

58. Almost ALL plant species depend on mycorrhizae to some extent
Types of mycorrhizae
Plant partners
Vesicular-arbuscular (VAM)
~150 species of fungi
Nearly all terrestrial plants (200,000 species including grasses, crops, flowering plants, and flowering trees not listed below)
Ectomycorrhizae
~5,000-10,000 species of fungi
Conifer trees, oaks, birches, beeches, Eucalyptus)
(~2000 species of trees)
See table on overhead for more info
Other types are:
Ericoid (Heath family)
Arbutoid (Heath family)
Orchid
Monotropoid

59. Effect of mycorrhizal symbiosis (with a fungus) on pine seedlings
Mycorrhizal fungi increase survival and growth of seedlings

60. LEARNING OBJECTIVE 6
Characterize the unique nature of a lichen

61. KEY TERMS
LICHEN
A compound organism consisting of a symbiotic fungus and an alga or cyanobacterium
Lichens have three main growth forms: crustose, foliose, and fruticose

62. Lichens

63. Fruticose lichen (Ramalina)
Surface
layer
(fungal hyphae)
Soredia
Fungal hyphae
interwoven with
photosynthetic
organism
Loosely
woven hyphae
Bottom layer
(fungal hyphae)
Rock or other surface
to which lichen is attached
Crustose lichens
(Bacidia, Lecanora)
This cross section of a typical
lichen shows distinct layers. The soredium, an asexual reproductive structure, consists of clusters of
algal or cyanobacterial cells
enclosed by fungal hyphae.
Figure 21.16: Lichens.
Foliose lichen
(Parmelia)
(b) Lichens vary in color, shape, and overall
appearance. Three growth forms–crustose, foliose,
and fruticose–are shown on a maple branch in
Washington State.
Fig , p. 420

64. Recap of mycorrhizal benefits
Greater plant productivity
(larger profits in the timber, fiber industries)
Greater reproductive success for plants (higher yields for agriculture)
Greater ecosystem stability
(Lewis & Koide 1990, Stanley et al. 1993).
Write on white board:
Benefits to plant from mycorrhizal association
1. Increased plant nutrient supply by extending the volume of soil accessible to plants.
2. Increased plant nutrient supply by acquiring nutrient forms that would not normally be available to plants.
3. Increased drought tolerance.
4. Protection from parasitic fungi and nematodes.
5. Link plants together in physiological networks
Root colonisation by ECM and VAM fungi can provide protection from parasitic fungi and nematodes (Duchesne et al. 1989, Grandmaison et al. 1993, Newsham et al. 1995, Little & Maun 1996, Cordier et al. 1998, Morin et al. 1999).
Suppression of competing non-host plants, by mycorrhizal fungi has been observed (Allen et al. 1989).
Significant amounts of carbon transfer through ECM fungus mycelia connecting different plant species has been measured (Simard et al. 1997). This could reduce competition between plants and contribute to the stability and diversity of ecosystems.
Networks of hyphae supported by dominant trees may help seedlings become established or contribute to the growth of shaded understorey plants (Hogberg et al. 1999, Horton et al. 1999).
Nutrient transfer from dead to living plants can occur (Eason et al. 1991).
Left: No mycorrhizal fungi
Right: With mycorrhizal fungi

65. Economic Impact Foods: Food production:
Mushrooms, morels, truffles
Food production:
Beer, wine, bread, cheeses, soy sauce
Production of industrial chemicals:
Citric acid

66. LEARNING OBJECTIVE 7
Summarize some of the ways that fungi impact humans economically

67. Economic Impact Foods: Food production:
Mushrooms, morels, truffles
Food production:
Beer, wine, bread, cheeses, soy sauce
Production of industrial chemicals:
Citric acid

68. Fungal Food Products

69. Edible Ascomycetes

70. LEARNING OBJECTIVE 8
Summarize the importance of fungi to biology and medicine

71. Biology and Medicine 1 Production of medications:
Penicillin and other antibiotics
Cause important plant diseases:
Wheat rust, Dutch elm disease, chestnut blight

72. Biology and Medicine 2 Opportunistic pathogens in humans:
Ringworm, athlete’s foot, candidiasis, histoplasmosis
Produce mycotoxins:
Aflatoxins cause liver damage and cancer

73. The Destroying Angel

74. Ergot

75. Ergot
Figure 21.20: Claviceps purpurea infecting rye flowers.
This fungus produces a brownish black structure called an ergot (left ) where a seed would normally form in the grain head. A healthy grain head is shown for comparison (right ).
Fig , p. 423

76. Fungal Parasite

77. Spore Hypha Epidermis Stoma Leaf Air space Haustoria
Figure 21.21: How a fungus parasitizes a plant.
In this example, the hypha enters the leaf through a stoma. As the hypha grows, it branches extensively through the internal air spaces and penetrates plant cells with specialized hyphal extensions called haustoria.
Haustoria
Fig , p. 424

78. Fungal Plant Pathogens