1. What is the biggest organism ever?
Apatosaurus?
Blue whale?
Coast redwood?

2. 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)

3. Chapter 31
Fungi

4. Fungal Origins Ancestral eukaryote Figure 28.4 Fungi
Diplomonadida
Choanoflagellates
Parabasala
Euglenozoa
Fungi
Cercozoa
Radiolaria
Animalia
Rhodophyta
Chlorophyta
Plantae
Alveolata
Stramenopila
Amoebozoa
The paraphyletic group “Protists,” along with Animalia, Plantae & Fungi.
Ancestral eukaryote
Figure 28.4

5. Fungal Form and Function
Anatomy
Hyphae and mycelium
Hyphae- thread-like
filaments, one cell thick
Reproductive
structure or fruiting body
See Fig. 31.2
Mycelium – interwoven mass of hyphae

6. Fungal Form and Function
Anatomy
Hyphae and mycelium
Mycelium
Hyphae

7. Fungal Form and Function
Anatomy
Aseptate hypha,
a.k.a. coenocytic
Septate hypha
See Fig. 31.3

8. Fungal Form and Function
Anatomy
Cell walls contain chitin

9. Fungal Form and Function
Immobile adults

10. Fungal Form and Function
Unlike plants and animals,
no distinct embryo is formed
during early development

11. 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

12. 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

13. 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

14. Fungal Life Cycles Reproduction Asexual – default mode under stable
conditions; spores are produced

15. Fungal Life Cycles Haploid (1n) spores are produced by mitosis
Key
Haploid (1n) spores
are produced by
mitosis
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
Spores are genetically
identical to original
mycelium
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
Spores disperse and
germinate to
produce new
myceliun
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

16. 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)

17. Sexual reproduction in fungi+ –
hyphae (n)
fusion of compatible hyphae (plasmogamy)
fused hyphae (n + n)
dispersal of spores
zygote (2n)
sexual spores (n) + –
fusion of nuclei (karyogamy)
zygotes (2n)
meiosis of “zygote-like” structures

18. Sexual reproduction in fungi
Haploid spores may disperse long distances away from the fruiting body

19. Fungal Life Cycles Fusion of compatible hyphae (plasmogamy)
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

20. Fungal Life Cycles Fusion of compatible hyphae (plasmogamy)
…initiates a heterokaryotic phase
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

21. Fungal Life Cycles Fusion of nuclei (karyogamy) See Fig. 31.5 Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

22. Fungal Life Cycles Fusion of nuclei (karyogamy)
…initiates a zygotic phase
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

23. Fungal Life Cycles Fusion of nuclei (karyogamy)
…initiates a zygotic phase
…which is perhaps best described as “zygote like”
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

24. Fungal Life Cycles
Meiosis in “zygote-like” cells produces spores or cells that will produce spores
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

25. Both asexual & sexual reproduction produce haploid spores
Fungal Life Cycles
Both asexual & sexual reproduction produce haploid spores
Key
Haploid (n)
Heterokaryotic
stage
Heterokaryotic
PLASMOGAMY
(fusion of cytoplasm)
Diploid (2n)
KARYOGAMY
(fusion of nuclei)
Spore-producing
structures
SEXUAL
REPRODUCTION
Zygote
Spores
ASEXUAL
REPRODUCTION
Mycelium
MEIOSIS
GERMINATION
GERMINATION
Spore-producing
structures
Spores
See Fig. 31.5

26. Fugal Diversity 5 phyla Over 100,000 species described
Chytrids
Zygote fungi
Arbuscular mycorrhizal fungi
Sac fungi
Club fungi
Chytridiomycota
Zygomycota
Glomeromycota
Ascomycota
Basidiomycota
Over 100,000 species described
Over 1000 additional species described each year
Loss of flagella*
5 phyla
See Fig. 31.9
*Flagella may have been lost multiple
times in the fist two lineages

27. Classification of Fungi
Phylum: Chytrids
Ancient group – diverged earliest from the other fungi

28. Classification of Fungi
Phylum: Chytrids
Ancient group – diverged earliest from the other fungi
Aquatic –
the only fungi with flagellated spores (zoospores)

29. Sexual reproduction in a chytrid:
flagellated spores
spores

30. 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

31. Classification of Fungi
Phylum: Zygomycetes = Zygote fungi
Sexual reproduction via zygosporangia (resistant heterokaryons) that produce genetically variable spores

32. See Fig. 31.12 Black Bread Mold Key Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Plasmogamy
Mating type (-)
Mating type (+)
Sexual reproduction
Zygosporangium
Karyogamy
Asexual
reproduction
Meiosis
See Fig

33. 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

34. See Fig. 31.12 Black Bread Mold Key Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)
Plasmogamy
Mating type (-)
Mating type (+)
Sexual Reproduction
Zygosporangium
Karyogamy
Asexual
Reproduction
Meiosis
See Fig

35. 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

36. 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

37. Classification of Fungi
Phylum: Glomeromycetes = Arbuscular mycorrhizae
Associated with ~90% of plant species

38. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sexual reproduction via spores produced in asci (sac-like cases)

39. Ascocarp, ascus, and ascospores
Neurospora
Key
Haploid (1n)
Heterokaryotic (1n + 1n)
Conidia of mating type (-)
Diploid (2n)
Asexual
Reproduction
Plasmogamy
Hyphae of mating type (+)
Karyogamy
Sexual Reproduction
Meiosis
See Fig
Ascocarp, ascus, and ascospores

40. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sexual reproduction via spores produced in asci (sac-like cases)
Asexual reproduction via naked spores (conidia)

41. Ascocarp, ascus, and ascospores
Neurospora: an ascomycete
Key
Haploid (1n)
Heterokaryotic (1n + 1n)
Conidia of mating type (-)
Diploid (2n)
Asexual
Reproduction
Plasmogamy
Hyphae of mating type (+)
Karyogamy
Sexual Reproduction
Meiosis
See Fig
Ascocarp, ascus, and ascospores

42. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Many saprobic species, e.g., Scarlet cups

43. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Many parasites, especially of plants, but also of animals, e.g., Candida yeasts

44. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Many symbionts with plants, e.g., truffles

45. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Morels – Delicacy or deadly

46. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sources of many interesting chemicals
E.g., Penicillium – the source of penicillin
Penicillium growing on an orange and inhibiting a plated streak of Staphylococcous bacteria.

47. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
Sources of many interesting chemicals
E.g., the source of LSD

48. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
The yeasts used to brew beer…

49. Classification of Fungi
Phylum: Ascomycetes = Sac fungi
…and bake breads and pizza crusts…

50. Classification of Fungi
…but the mushrooms that top your pizza come from a different phylum…

51. Classification of Fungi
Phylum: Basidiomycetes = Club fungi
Include:
common mushroom, puffballs,
stink horns, shelf fungi,
plant-parasitic smuts & rusts

53. 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

54. Basidia with basidiospores
A mushroom-forming basidiomycete
Plasmogamy
See Fig
Basidiocarp
Mating type (-)
Mating type (+)
Sexual Reproduction
Basidia with basidiospores
Karyogamy
Meiosis
Key
Haploid (1n)
Heterokaryotic (1n + 1n)
Diploid (2n)

55. 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

56. Phylum: Basidiomycetes = Club fungi
Fruiting bodies of the “inky cap” mushroom

57. Phylum: Basidiomycetes = Club fungi
Basidia are generally found on the surface of gills
gills
basidiospores

58. Phylum: Basidiomycetes = Club fungi
Basidia are generally found on the surface of gills
gills
basidiospores

59. Amanita spore pattern Phylum: Basidiomycetes = Club fungi
Basidia are generally found on the surface of gills
Amanita spore pattern

60. Phylum: Basidiomycetes = Club fungi
Giant puffball
Shelf fungi

61. Phylum: Basidiomycetes = Club fungi
Parasitic corn smut

62. Classification of Fungi
Deuteromycetes - Imperfect Fungi
Eclectic group of unclassified species

63. 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

64. 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)

65. 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

66. 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

67. Functional Biology of Fungi
Mycorrhizae
Symbiotic associations with plants (representatives known from all fungal phyla, not just Glomeromycetes)

68. Functional Biology of Fungi
Lichens
Obligate symbiotic associations with algae or cyanobacteria

69. Functional Biology of Fungi
Parasites
Chestnut blight
Ringworm

70. Functional Biology of Fungi
Toxin producers
Aflatoxin

71. Functional Biology of Fungi
Biotic control agents
The first antibiotic used by humans
Staphylococcus
Penicillium
Zone of inhibited growth

72. Functional Biology of Fungi
Biotic control agents
Used against termites, rice weevils, etc.

73. 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

74. 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

75. 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