1. Kingdom Fungi

2. Characteristics

3. The Characteristics of Fungi
Fungi are NOT plants
Nonphotosynthetic
Eukaryotes
Nonmotile
Most are saprobes (live on dead organisms)

4. The Characteristics of Fungi
Absorptive heterotrophs (digest food first & then absorb it into their bodies
Release digestive enzymes to break down organic material or their host
Store food energy as glycogen
BREAD MOLD

5. The Characteristics of Fungi
Important decomposers & recyclers of nutrients in the environment
Most are multicellular, except unicellular yeast
Lack true roots, stems or leaves
MULTICELLULAR MUSHROOM
UNICELLULAR YEAST

6. The Characteristics of Fungi
Cell walls are made of chitin (complex polysaccharide)
Body is called the Thallus
Grow as microscopic tubes or filaments called hyphae

7. The Characteristics of Fungi
Some fungi are internal or external parasites
A few fungi act like predators & capture prey like roundworms
Predaceous Fungi feeding on a Nematode (roundworm)

8. The Characteristics of Fungi
Some are edible, while others are poisonous
EDIBLE
POISONOUS

9. The Characteristics of Fungi
Produce both sexual and asexual spores
Classified by their sexual reproductive structures
Spores come in various shapes

10. The Characteristics of Fungi
Grow best in warm, moist environments
Mycology is the study of fungi
Mycologists study fungi
A fungicide is a chemical used to kill fungi
Fungicide kills leaf fungus

11. The Characteristics of Fungi
Fungi include puffballs, yeasts, mushrooms, toadstools, rusts, ringworm, and molds
The antibiotic penicillin is made by the Penicillium mold
Penicillium mold
Puffball

12. Vegetative Structures
NON-REPRODUCTIVE

13. Hyphae Tubular shape ONE continuous cell
Filled with cytoplasm & nuclei
Multinucleate
Hard cell wall of chitin also in insect exoskeletons

14. Hyphae
Stolons – horizontal hyphae that connect groups of hyphae to each other
Rhizoids – rootlike parts of hyphae that anchor the fungus
STOLON
RHIZOIDS

15. Hyphae Cross-walls called SEPTA may form compartments
Septa have pores for movement of cytoplasm
Form network called mycelia that run through the thallus (body)

16. ASEXUAL & SEXUAL SPORES
REPRODUCTIVE STRUCTURES
ASEXUAL & SEXUAL SPORES

17. REPRODUCTION Most fungi reproduce Asexually and Sexually by spores
ASEXUAL reproduction is most common method & produces genetically identical organisms
Fungi reproduce SEXUALLY when conditions are poor & nutrients scarce

18. Spores Spores are an adaptation to life on land
Ensure that the species will disperse to new locations
Each spore contains a reproductive cell that forms a new organism
Nonmotile
Dispersed by wind

19. Sexual Reproduction

20. SEXUAL REPRODUCTION
Used when environmental conditions are poor (lack of nutrients, space, moisture…)
No male or female fungi
Some fungi show dimorphism
May grow as MYCELIA or a YEAST –LIKE state (Filament at 25oC & Round at 37oC)
Dimorphic Fungi

21. - + SEXUAL REPRODUCTION
Haploid 1n hyphae from 2 mating types (+ and -) FUSE (Fertilization)
Forms a hyphae with 2 nuclei that becomes a ZYGOTE
The zygote divides to make a SPORE - +
SPORE FORMS

22. ASexual Reproduction

23. Three types of Asexual Reproduction
Fragmentation – part of the mycelium becomes separated & begins a life of its own
Budding – a small cell forms & gets pinched off as it grows to full size
Used by yeasts
Asexual spores – production of spores by a single mycelium

24. Reproduce by spores Spores may be Formed: Directly on hyphae
Inside sporangia
On Fruiting bodies
Penicillium hyphae
Fungi reproduce by releasing spores that are produced either sexually or asexually.
The output of spores from one reproductive structure is enormous, with the number reaching into the trillions.
Dispersed widely by wind or water, spores germinate to produce mycelia if they land in a moist place where there is food.
Pilobolus sporangia
Amanita fruiting body

25. ASEXUAL REPRODUCTION
Fruiting Bodies are modified hyphae that make asexual spores
An upright stalk called the Sporangiosphore supports the spore case or Sporangium

26. Types of Fruiting Bodies: Basidia Sporangia Ascus
ASEXUAL REPRODUCTION
Types of Fruiting Bodies:
Basidia
Sporangia
Ascus
Sporangia
Basidia

27. Both are composed of hyphae
Fruiting Bodies
Both are composed of hyphae
mycelium

28. It’s All About the Spores!
Fungi are classified by their REPRODUCTIVE STRUCTURES and SPORES
The reproductive structures are:
BASIDIA - BASIDIOMYCOTA
SPORANGIA - ZYGOSPORANGIA
ASCUS - ASCOMYCOTA

29. Major Groups of Fungi

30. Fungal NUTRITION Saprobes Parasites Mutualists Decomposers
Molds, mushrooms, etc.
Parasites
Harm host
Rusts (attack plants)
Mutualists
Both benefit
Lichens
Mycorrhizas
fungi absorb nutrients from nonliving organisms.
Parasitic fungi absorb nutrients from the cells of living hosts. Saprobic
Some parasitic fungi, including some that infect humans and plants, are pathogenic.
Mutualistic fungi also absorb nutrients from a host organism, but they reciprocate with functions that benefit their partner in some way

31. Major Groups of Fungi Basidiomycota – Club Fungi
Zygomycota – Bread Molds
AM Fungi (mycorrhizas) –
Ascomycota – Sac Fungi
Lichens – Symbiosis (algae & Fungi)

32. ZYGOmycota

33. Rhizopus on strawberries
Zygomycota
Rhizopus on strawberries
Called the sporangium fungi
Commonly called molds
Also includes blights
Hyphae have no cross walls (aseptate)
Grow rapidly
Includes bread mold Rhizopus stolonifer
Tomato Blight
Most of the 600 zygomycote, or zygote fungi, are terrestrial, living in soil or on decaying plant and animal material.
Asexual reproduction in sporangia
One zygomycote group form mycorrhizas, mutualistic associations with the roots of plants.

34. Basidiomycota

35. Basidiomycota Called Club fungi Includes: Mushrooms Toadstools
Bracket & Shelf fungi
Puffballs
Stinkhorns
Rusts
Asexual spores conidia
Ecologically important on wood as decomposers and parasites
Half the mushrooms form mycorrhizas

36. Basidomycetes: Club Fungi
Mushrooms are the most common club fungi. Others include rusts that harm crop plants.
The visible mushroom is merely a fruiting body. The bulk of the organism is underground, a mat of hyphae (strands) called a mycelium that can be quite large. One example in Oregon covers 2200 acres (3 ½ square miles), to a depth of 3 feet, and it is at least 2400 years old.

37. Ascomycota – “sac fungi”
Sex. – asci
Asex. – common
Cup fungi, morels, truffles
Important plant parasites & saprobes
Yeast - Saccharomyces
Most lichens
Mycologists have described over 60,000 species of ascomycetes, or sac fungi.
Ascomycota tend to grow from spore to spore in one year and relate well to living plant tissues
There is diverse form in the growth and fruiting structures – yeasts to morels, many intermediate (and small)
Asexual reproduction by conidia (externally produced, not in sporangia)
Half of the Ascomycota form lichens (evolved 8 or more times in different orders) but not all lichens are Ascomycotes
A cluster of asci with spores inside

38. Ascomycetes Ascomycetes are sac fungi: they produce spores in sacs.
Truffles and morels are good examples of ascomycetes: they taste good!
Penicillium, the mold that gave penicillin, the first antibiotic, is an ascomycete. Penicillium also gives flavor to certain cheeses.
Sac fungi also include some important single celled yeasts. Saccharomyces cerevesiae is used to make bread rise and also to ferment beer and wine. Candida albicans produces the common human yeast infections.

39. Yeasts Single celled fungi Adapted to liquids Plant saps Water films
Moist animal tissues
Bread and wine yeast, the budding yeast, Saccharomyces
Easily cultured. For a time, this was the most important organism for studying the molecular genetics of eukaryotes
Thus, Saccharomyces is arguably the most important organism known to humans
Candida causes diseases of humans, usually experiencing chemical imbalance or immune problems
Candida
Saccharomyces

40. Schizosaccharomyces octospora – fermenter of Palm Wine
This yeast is isolated from palm wine (fermented sap of the oil palm in West Africa)
Note that it is forming 8-spored asci (“octospora”) – an indication that it is an Ascomycote
10 μm

41. Molds Rapidly growth Asexual spores Many human importances
Food spoilage
Food products
Antibiotics, etc.
A mold is a rapidly growing, asexually reproducing fungus.
The mycelia of these fungi grow as saprobes or parasites on a variety of substrates.
Also used in foods (Blue cheese, Tempeh) and in industrial production of drugs
Early in life, a mold, a term that applies properly only to the asexual stage, produces asexual spores.
Later, the same fungus may reproduce sexually, producing zygosporangia, ascocarps, or basidiocarps
Some molds go through a “fake sex” process
Noble Rot - Botrytis
Fig Antibiotic activity

42. Mycorrhizas “Fungus roots” Mutualism between: Several kinds
Fungus (nutrient & water uptake for plant)
Plant (carbohydrate for fungus)
Several kinds
Zygomycota – hyphae invade root cells
Ascomycota & Basidiomycota – hyphae invade root but don’t penetrate cells
Extremely important ecological role of fungi!
Half of the mushroom-forming fungi (basidiomycota) form mycorrhizas with trees
Some people think that the spongy tissue in roots evolved as a place where fungi could invade to form early links with plants that helped them survive the harsh life on early earth

43. Lichens “Mutualism” between Form a thallus Fungus – structure
Alga or cyanobacterium – provides food
Form a thallus
Thallus is a plant-like body that doesn’t have roots, stems or leaves
Thallus doesn’t look like either partner
Dual nature of thalli was not fully understood until early 1900’s
Fungus gives the name to the lichen (by agreement)
Fungus usually, but not always, an Ascomycote (in 8+ independent orders)
Algae green. If bluegreen bacteria present, lichens fix nitrogen (turn atmospheric nitrogen into amino acid nitrogen in proteins)
Fig 31.16

44. Lichen internal structure
Fig 31.17
The nature of lichen symbiosis is may also be described as mutual exploitation instead of mutual benefit.
Lichens live in environments where neither fungi nor algae could live alone.
While the fungi do not not grow alone in the wild, some (but not all) lichen algae occur as free-living organisms.
If cultured separately, the fungi do not produce lichen compounds and the algae do not “leak” carbohydrate from their cells.
In some lichens, the fungus invades algal cells with haustoria and kills some of them, but not as fast as the algae replenish its numbers by reproduction.
Lobaria oregana prefers old-growth conifer canopies in forests with clean air.
Lobaria

45. Summary: What do fungi eat?
Heterotrophs (cannot make their own food like plants)
Extracellular, absorptive nutrition secrete enzymes outside of their bodies, “digest” the food outside of their cells and then absorb the molecules into their cells.
Live in their substrate (food)
How is this similar to us? What consequences/ advantages does it have?

46. Fungi are made of hyphae (cells joined in thread-like strands)
MODULAR GROWTH - FRAGMENTATION = ASEXUAL REPRODUCTION!!

47. Mushrooms are for sexual reproduction (~flowers) Mycelium = body of the fungus
Hyphae = the “bricks” from which the mushroom is built

48. Recap: Definition of fungus
Single or multi-celled eukaryote with heterotrophic, absorptive nutrition, chitinous cell walls, and which stores energy as glycogen
Live in food source or go dormant in low humidity

49. 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)

50. What would happen if wood was not decomposed?
Tasmanian Forests, and logging activities in them
All photos by Geoff Law unless otherwise credited

51. Fungi are important decomposers!
Fungi are the only organisms that can completely decompose lignin (what makes wood hard)
Lignin must be broken down before any other decomposition can occur (no fungi = no decomposition by anyone).
Fungi also decompose cellulose to glucose and play a major role in the global carbon cycle.
Fungi can break down lignin and cellulose (two most abundant organic molecules on earth)
basiodiomycetes are only organisms that can break lignin down to CO2
lignin perioxidase breaks down lignin in “enzymatic combustion” removes electron from lignin molecule creating a free radical which leads to a series of uncontrolled and unpredictable reactions. Why have other organisms not evolved this ability? only save to do extracellularly. Very generalized enzyme (not specific) lignin highly variable molecule - combustion not used to harvest energy, purely to release cellulose from lignin matrix so can be digested. (Fungal “miners”)

52. Why should you care about fungi?
A few reasons:
They make foods we like to eat
Mycorrhizae are responsible for plant life on land and high productivity rates
They decompose wood and organic matter
Penicillin and other antibiotics
They’re just really cool!