1. Fungi
Chapter 31

2. Fungi

3. Fungi

4. Fungi

5. Fungi More closely related to animals than plants Unicellular
Most are multi-cellular
Tropics to tundra
Aquatics to terrestrial
Airborne spores
Yeast in breads & beer

7. Fungi Decomposers Recycle nutrients
Help roots of plants absorb nutrients
Disease causing (plants and animals)
Treatment difficult

8. Body structure Hyphae Tiny filaments Composed of cytoplasm
Surrounded by plasma membrane & cell wall
Cell wall made of chitin
Septa
Cross-walls that separate cells of hyphae

9. Hyphae

10. Cell wall Cell wall Nuclei Pore Septum Nuclei (a) Septate hypha
Fig. 31-3
Cell wall
Cell wall
Nuclei
Pore
Septum
Nuclei
Figure 31.3 Two forms of hyphae
(a) Septate hypha
(b) Coenocytic hypha

11. Body structure Mycelium: Mass of connected hyphae
Surrounds & infiltrates material
Maximizes contact with material
Grows rapidly
Grows underground so not visible

13. Figure A fairy ring

14. Reproduction Each cell can have one or more nuclei Monokaryotic:
One nuclei
Dikaryotic:
Two haploid nuclei that function independently

15. Reproduction Dikaryotic hyphae Heterokaryotic:
Nuclei that are from two genetically distinct individuals
Homokaryotic:
Nuclei are genetically similar

16. Reproduction Sexually Asexually Spores are produced either way
Spread by wind or on insects
Suitable environment give rise to new fungal mycelium

18. Reproduction Sexual reproduction 2 compatible mating types fuse
Usually 2 haploid fuse to form diploid
Some fungi remain 1n + 1n and not 2n
+/- length of time

19. Reproduction Plasmogamy: Fusion of cytoplasm of mycelia Karyogamy:
Fusion of nuclei
Zygotes
Meiosis
Spore formation

20. Reproduction Asexually Molds Produce haploid spores by mitosis Yeasts
Buds

21. 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

22. Fungi Heterotrophs Secrete hydrolytic enzymes (exoenzymes)
Absorb nutrients(organic molecules)

23. Nutrients Digest wood (cellulose) Absorb the glucose
Lignin (found in wood)
Decomposer of living or dead organisms
Yield carbon, nitrogen and phosphorus

24. Nutrients Obtain nutrients from tiny roundworms called nematodes
Paralyze
Penetrate
Absorb nutrients from body
Nitrogen source

25. Metabolic pathways Anaerobic fermentation Wines & cheeses Soy sauce
Antibiotics & steroids
Yeasts (single cell fungi)
Bioremediation
Using organisms to break up a toxin

26. Symbiosis Lichens Fungus & photosynthetic partner (algae)
Mutualism some are parasitic
Hyphae penetrate cell walls of algae
Obtain nutrients from the algae
Protects the algae from too much sun

27. Symbiosis Lichens first to invade a harsh environment
Colored - pigments -protect the algae from the sun
Pigments are used as natural dyes

28. Lichen

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

30. Mycorrhizae Tree (plant) roots with fungi
Fungi function as an extension of roots
Plants absorb more nutrients, such as Zn, P, Cu
Fungi gets organic materials from the plant

31. Mycorrhizae 1. Arbuscular: Fungal hyphae penetrate the trees roots
Form coils around roots
More common
2. Ectomycorrhizae:
Hyphae do not penetrate the roots
Helps trees grow in infertile areas

33. Endophytes Fungus lives inside the plant Intercellular spaces
Help defend plant against herbivores
Symbiotic relationship between fungi & ruminant animals
Fungi helps digest the cellulose

34. Parasitic Mycosis Fungal infection Ringworm Athlete’s foot
Candida albicans

35. Parasitic Aspergillus Produces toxin harmful to humans. Pneumocystis
Causes a rare pneumonia in AIDS patients
Chytridomycosis
Fungal infection that harms amphibians
Other fungal infections harm plants
Chestnut trees, corn

37. Distinguishing Features
Figure 31.UN07
Fungal Phylum
Distinguishing Features
Chytridiomycota (chytrids)
Flagellated spores
Zygomycota (zygomycetes)
Resistant zygosporangium as sexual stage
Glomeromycota (arbuscular mycorrhizal fungi)
Arbuscular mycorrhizae formed with plants
Ascomycota (ascomycetes)
Sexual spores (ascospores) borne internally in sacs called asci; vast numbers of asexual spores (conidia) produced
Figure 31.UN07 Summary of key concepts: fungi lineages
Basidiomycota (basidiomycetes)
Elaborate fruiting body (basidiocarp) containing many basidia that produce sexual spores (basidiospores)

38. Fungi Mycologists: scientists that study fungus Five groups
1. Chytrids
2. Zygomycetes
3. Glomeromycetes
4. Ascomycetes
5. Basidiomycetes

39. 1. Chytridiomycota (chytrids)
Aquatic fungi
Flagellated spores called zoospores
Diverged earliest
Chitin in the cell walls

40. 2. Zygomycota Bread molds Fruit molds Zygosporangium:
Contains one or more diploid nuclei
Forms a hard covering
Good growth conditions
Undergoes meiosis then mitosis
Releases spores

42. Zygomycota Key Haploid (n) Heterokaryotic (n + n) Diploid (2n) Mating
PLASMOGAMY
Mating
type (+)
Gametangia with
haploid nuclei
Mating
type (–)
100 µm
Young
zygosporangium
(heterokaryotic)
Rhizopus
growing
on bread
SEXUAL
REPRODUCTION
Dispersal and
germination
Zygosporangium
Sporangia
KARYOGAMY
Spores
Diploid
nuclei
Sporangium
ASEXUAL
REPRODUCTION
MEIOSIS
Dispersal and
germination
50 µm
Mycelium

43. BREAD MOLD

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

45. 3. Glomeromycetes Arbuscular mycorrhizae Hyphae with plant roots
Very few species

46. 4. Ascomycetes Sac fungi Marine, freshwater & terrestrial Yeast
Asci: sac like structure containing sexual spores
Ascocarps: contain asci
Fruiting bodies
Microscopic or macroscopic

47. Key Ascomycota Conidia; mating type (–) Haploid spores (conidia)
Haploid (n)
Dikaryotic (n + n)
Diploid (2n)
Dispersal
Germination
Mating
type (+)
ASEXUAL
REPRODUCTION
Hypha
PLASMOGAMY
Ascus
(dikaryotic)
Conidiophore
Mycelia
Dikaryotic
hyphae
Mycelium
Germination
SEXUAL
REPRODUCTION
KARYOGAMY
Dispersal
Diploid nucleus
(zygote)
Asci
Eight
ascospores
Ascocarp
Four
haploid
nuclei
MEIOSIS

48. YEAST

49. Morchella esculenta Tuber melanosporum Figure 31.15
Figure Ascomycetes (sac fungi)
Morchella esculenta
Tuber melanosporum

50. 5. Blasidiomycetes Mushrooms, shelf fungi, puff balls
Blasidium (Latin means “little pedestal”)
Long-lived dikaryotic mycelium
Leads to more genetic re-combinations
Blasidiocarps (mushroom)
Produced sexually
Fruiting bodies
Wood decomposers

51. Blasidiomycetes Dikaryotic mycelium Haploid mycelia Mating type (–)
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
Basidium containing
four haploid nuclei
KARYOGAMY
MEIOSIS
Key
Haploid (n)
Dikaryotic (n +n)
Diploid
nuclei
1 µm
Basidiospore
Diploid (2n)

52. Maiden veil fungus Figure 31.17c
Figure 31.17c Basidiomycetes (club fungi) (part 3: maiden veil fungus)
Maiden veil fungus