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FUNGI Lecturer: Asst. Prof. Dr. İsmail EKER.

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1 FUNGI Lecturer: Asst. Prof. Dr. İsmail EKER

2 FUNGI KINGDOM PROTISTA KINGDOM FUNGI Acrasiomycota Zoomycota
(cellular slime molds) Myxomycota (plasmodial slime molds) Slime molds Without cell wall Zoomycota (bread molds) Ascomycota (sac fungi) Basidiomycota (club fungi) Terrestrial Higher true molds Oomycota (water molds) Chytridiomycota (chytrids) Primitive molds Aquatic Deuteromycota (imperfect fungi)

3 SLIME MOLDS Vegetative thallus – lacks a cell wall,
move about like amoeba, resemble some protozoa, ingests food particles by phagocytosis, inhabit damp soils, especially areas rich in decomposing plant material, May be multinucleate (Plasmodial SM) or independent amoeboid cell (Cellular SM)

4 Phylum Acrasiomycota (Cellular slime molds)
3 genera, 50 spp. Vegetative thallus – amoeboid cells that aggregate to form pseudoplasmodium produce walled spores during reproduction Cellular slime molds contain cellulose in their spore wall widespread in forest soils, dung, decaying plant matter Feed on bacteria in soil as amoeboid cells without flagella

5 Cellular Slime Molds Life Cycle

6 Dictyostelium discoideum

7 (Plasmodial slime molds, True slime molds)
Phylum Myxomycota (Plasmodial slime molds, True slime molds) 71 genera, 500 spp. vegetative thallus – plasmodium nucleus replicates without dividing to form multinucleated feeding mass do not contain cellulose may contain 2 flagella in reproductive cells only Fuligo septica

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9 Physarum polycephalum

10 Physarum virescens

11 KINGDOM FUNGI (TRUE MOLDS, EUMYCOTA)

12 GENERAL CHARACTERISTICS OF FUNGI
Eukaryotic heterotrophs that digest food externally and absorb the the digested materials through their body walls. Many are ecologically important saprophytes (consume dead and decaying matter). Others are parasites or mutualists. Parasitic fungi absorb nutrients from their host through specialized hyphae called haustoria. Over 100,000 fungal species identified. It is estimated there are actually 1.5 million species of fungi Only about 100 are human or animal pathogens. Most human fungal infections occur in immunocompromised individuals (opportunistic infections). Fungal diseases in plants cause over 1 billion dollars/year in losses. Multicellular, but yeasts are unicellular. Most are aerobes or facultative anaerobes. Cell walls are made up of chitin (polysaccharide). Reproduce sexually and asexually Asexually by spores Sexually by mating of hyphae filaments from two genetically different fungi Fungi are classified by the shape of their sporangium and the way they produce sexual spores.

13 Hyphae are the basic structure of threadlike filaments that grow from a fungal spore.
Hyphae grow into a mycelium – a cottony mass covering and distributed within whatever the fungus is feeding on. Coenocytic hyphae where the nucleis of each cell is embedded in the cytoplasm without a cell wall. Eg. Zygomycota, Oomycota Hyphae with cross walls Eg. Basidiomycota, Ascomycota Hyphae without cross walls

14 Spore-producing structures
Generalized Life Cycle of Fungi Key Haploid (n)- most of the life cycle Heterokaryotic (Dikaryotik=n+n) Diploid (2n) Spore-producing structures Spores ASEXUAL REPRODUCTION Mycelium Figure 31.5 Generalized life cycle of fungi. GERMINATION

15 Spore-producing structures
although the cells fuse the nuclei don't; it is said to be dikaryotic Key Haploid (n) Heterokaryotic stage PLASMOGAMY Heterokaryotic (n+n) different hypha attracted by pheromones fuse Diploid (2n) Spore-producing structures from hours to centuries can go by before this takes effect KARYOGAMY SEXUAL REPRODUCTION Spores ASEXUAL REPRODUCTION Mycelium Zygote Figure 31.5 Generalized life cycle of fungi. GERMINATION

16 Spore-producing structures
Key Haploid (n) Heterokaryotic stage PLASMOGAMY Heterokaryotic (n+n) Diploid (2n) Spore-producing structures KARYOGAMY SEXUAL REPRODUCTION Spores ASEXUAL REPRODUCTION Mycelium Zygote Figure 31.5 Generalized life cycle of fungi. GERMINATION MEIOSIS GERMINATION Spores

17 Phylum Oomycota (Water Molds)
580 spp. finely branched single-celled filaments. Hyphae have multiple nuclei (Coenocytic/ aseptate) cell walls made of cellulose (like plant), not chitin reproductive cells with 2 flagella (like protists) diploid stage is dominant aquatic Cause diseases such as potato blight

18 LIFE CYCLE OF OOMYCOTA Oogonia

19 e.g. water molds (saprobes or parasites of fish)

20 downy mildews (plant parasites – potato blight)

21 Irish Potato Famine of 19th Century
Devastated potato crops, causing devastating starvation in Ireland  During Ireland’s potato famine in the 19th century, over a million people died of starvation and disease. Another 1.5 million emigrated to the other countries.

22 Phylum Chyridiomycota (Chytrids)
575 spp. Appear to be link between protists and fungi aquatic Saprobes or parasites Chytrids have flagellated spores (one flagella), called zoospores Feed on dead aquatic plants, detritus; frog parasites Forming Male Gametes Forming Female Gametes

23 Chytridiomycota (chytrids)

24 Fungal Parasites and Pathogens
The fungi Batrachochytrium dendrobatidis causes chitridiomycosis Appears to be significantly responsible for much of the worldwide decline in amphibian populations In 2004, an international convention of amphibian biologists announced that 32 percent of species are currently threatened, 43 percent were declining in population, and that between 9 and 122 species have become extinct since Currently, the Global Amphibian Assessment lists 427 species as "critically endangered.

25 Phylum Deuteromycota (Fungi imperfecti)
> 20,000 species of fungi in 2600 genera have no known sexual state Reproduce asexually. Most belong in phylum Ascomycota Catch-all category for unclassified fungi cause most fungal diseases in humans EX: ringworm, athletes foot, oral thrush and more: Pneumocystis carinii: Causes pneumonia in AIDS patients. Leading cause of death in AIDS patients. Originally classified as a protozoan. Candida albicans: Causes yeast infections of vagina in women. Opportunistic infections of mucous membranes in AIDS patients.

26 Resemble Ascomycetes, but their reproductive cycle has never been observed
Different from Ascomycetes because there is a definite lack of sexual reproduction, which is why they are called Imperfect Fungi Penicillium fungi Up Close

27 Penicillium sp.

28 Aspergillus sp.

29 Opportunistic Infection by Candida albicans in an AIDS Patient
Source: Atlas of Clinical Oral Pathology, 1999

30 Severe nail infection with Trichophyton rubrum in
a 37-year-old male AIDS patient. Source: Intern. J. Dermatol. 31(1992): 453.

31 Disseminated Histoplasma capsulatum, skin infection.
Source: Microbiology Perspectives, 1999.

32 Phylum Zygomycota (bread molds= Zygote fungi)
~600 species currently classified Mainly terrestrial Saprophytic molds with coenocytic hyphae (lack septa). Live in soil or on decaying organic matter Asexual Reproduction: Used most of the time. Sporangiospore: Asexual spore enclosed within a sporangium or sac at the end on an aerial hypha. Sexual Reproduction: Occurs through conjugation, the joining of hypha of two different strains (plus and minus). Zygospores: Sexual spores which are enclosed in a thick, resistant wall. Generally not pathogens. Rhizopus nigricans: Common black bread mold. May cause opportunistic infections in diabetes patients

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34 Life Cycle of a Zygomycete
PLASMOGAMY Mating type () Gametangia with haploid nuclei Mating type () Rhizopus growing on bread 100 m Young zygosporangium (heterokaryotic) SEXUAL REPRODUCTION Dispersal and germination Zygosporangium Flagellum KARYOGAMY Sporangia Figure The life cycle of the zygomycete Rhizopus stolonifer (black bread mold). Diploid nuclei Sporangium ASEXUAL REPRODUCTION MEIOSIS Key Dispersal and germination Haploid (n) Heterokaryotic (n  n) Mycelium 50 m Diploid (2n)

35 Phylum Ascomycota (sacfungi)
largest group of fungi (30,000 spp.) Molds with septate hyphae (e.g. cup fungi, morels and truffles) and some yeasts. most saprobic, live in marine, freshwater, and terrestrial habitats some pathogens of plants (Dutch elm disease, chestnut blight, ergot). ~Half live with algae as lichens Some form mycorrhizae produces two kinds of spores: sexual spores  ascospores (inside the ascus) asexual spores  conidia (naked)

36 The phylum is defined by production of sexual spores in saclike asci, usually contained in fruiting bodies called ascocarps. 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.

37 Truffles are round, warty, fungi that are irregular in shape
Truffles are round, warty, fungi that are irregular in shape. They vary from the size of a walnut to that of a man's fist. Since the times of the Greeks and Romans these fungi have been used in Europe as delicacies, as aphrodisiacs, and as medicines. They are among the most expensive of the world's natural foods, often commanding as much as $250 to $450 per pound. Truffles are harvested in Europe with the aid of female pigs or truffle dogs, which are able to detect the strong smell of mature truffles underneath the surface of the ground. The female pig becomes excited when she sniffs a chemical that is similar to the male swine sex pheromone.

38 Yeasts Unicellular fungi, nonfilamentous, typically oval or spherical cells. Reproduce asexually by budding or mitosis: Fission yeasts: Divide evenly to produce two new cells (Schizosaccharomyces). Budding yeasts: Divide unevenly by budding (Saccharomyces). Budding yeasts can form pseudohypha, a short chain of undetached cells. Candida albicans invade tissues through pseudohyphae. Yeasts are facultative anaerobes, which allows them to grow in a variety of environments. When oxygen is available, they carry out aerobic respiration. When oxygen is not available, they ferment carbohydrates to produce ethanol and carbon dioxide. Yeast can ferment carbohydrates. They break-down the glucose into ethanol and CO2. Used to make bread, beer and wine -Saccharomyces cerevisiae

39 Sacchromyces cerevisiae

40 Schizosaccharomyces pombe

41 Sacchromyces cerevisiae
Yeast Life Cycle 10 µm Parent cell Bud Sacchromyces cerevisiae Candida

42 LIFE CYCLE OF ASCOMYCOTA
Conidia; mating type () Key Dispersal Haploid (n) Germination Mating type () Dikaryotic (n  n) ASEXUAL REPRODUCTION Diploid (2n) Hypha PLASMOGAMY Ascus (dikaryotic) Conidiophore Mycelia Dikaryotic hyphae Mycelium Germination SEXUAL REPRODUCTION KARYOGAMY Dispersal Diploid nucleus (zygote) Asci Eight ascospores Ascocarp Figure The life cycle of Neurospora crassa, an ascomycete. Four haploid nuclei MEIOSIS

43 Sowerbyella rhenana

44 Peziza sp.

45 Morchella sp.

46 Tuber sp. (Truffle)

47 Ophiostoma ulmi (causes Dutch elm disease)

48 Cordyceps sp. Cordyceps includes about 400 identified species and many yet to be described. All Cordyceps species are endoparasitoids, mainly on insects and other arthropods (they are thus entomopathogenic fungi); a few are parasitic on other fungi. 25 µm ant Figure 31.4 Specialized hyphae moth fly

49 Phylum Basidiomycota (club fungi)
25,000 spp. Have septate hyphae. Include mushrooms, puffballs, bracket fungi, rusts, and smuts. Sexual Reproduction: Produce basidiospores formed on club-shaped basidia Asexual Reproduction: Through hyphae. some of them poisonous or cause plant diseases: Cryptococcus: Causes opportunistic respiratory and central nervous system infections in AIDS patients. Amanita: Mushroom produces lethal toxins to humans. Claviceps purpurea: Produces ergot toxin in wheat and rye.

50 Possess transient diploid basidium
Present on gills on underside of mushroom Shaped like a club by meiosis produces basidiospores ~1 billion released from a single mushroom

51 LIFE CYCLE OF BASIDIOMYCOTA
Dikaryotic mycelium Haploid mycelia PLASMOGAMY Mating type (–) Mating type (+) SEXUAL REPRODUCTION Figure The life cycle of a mushroom-forming basidiomycete Key Haploid (n) LIFE CYCLE OF BASIDIOMYCOTA Dikaryotic (n +n) Diploid (2n)

52 Dikaryotic mycelium Haploid mycelia Mating type (–) Mating type (+)
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)

53 Dikaryotic mycelium Haploid mycelia Mating type (–) Mating type (+)
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)

54 Dikaryotic mycelium Haploid mycelia Mating type (–) 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 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)

55 Amanita sp.

56 Agaricus sp.

57 Boletus sp.

58 Corpinus sp.

59 Lycoperdon sp. (puffball)

60 Puffballs emitting spores 70 trillion!
Figure Basidiomycetes (club fungi)

61 Trametes versicolor (Bracket fungus)

62 Geastrum triplex (Earth star fungus)

63 Clavaria zollingeri (Coral fungus)

64 Puccinia sp. (Rust fungi)
Wheat leaf rust on wheat

65 Ustilago sp. (Smut fungi)

66 · Many fungi are parasites on both plants and animals
Ecological Importance of Fungi · As decomposers, fungi breakdown organic matter and release nutrients back to the environment so that they can be used again ·  Many fungi are parasites on both plants and animals · Many form Mutualistic relationships with other organisms Lichens – association between a fungus and a green alga. Mycorrhizae – fungi that form associations with trees and plants

67 Economic importance of Fungi
Yeasts ferment sugar to produce alcohol Yeast through fermentation create air bubbles that causes bread to rise Unique flavors of certain cheeses are produced by fungi Soy sauce is produced by the fermentation of soy beans (via fungi) 200 species of edible basidiomycetes (morels, truffles, portabella…) Penicillium sp. is used to produce penicillin, widely used antibiotic Cyclosporine suppress immune responses in patients receiving organ transplants Some of the compounds produced in hospitals are used in controlled medical situations (stop uterine bleeding, treat high-blood pressure migraine head-aches) Fungi are also used as biocontrol agent Other fungi are grown commercially to produce certain chemicals (e.g., citric acid)

68 REPRODUCTION SYSTEMS IN FUNGI
1. budding 2. fission 3. bud fission 4. sporulation - asexual spore - sexual spore (fusion of 2 nucleic) Asexual (vegetative) reproduction * Formed by the aerial hyphae of one organism. New organisms are identical to parent. Sexual (generative) reproduction * Formed by the fusion of nuclei from two opposite mating strains of the same species. New organisms are different from both parents. SEXUAL SPORES ASEXUAL SPORES Ascospore Basidiospore Zygospore Oospore Sporangiospore Conidiospore Arthrospore/Oidospore Klamidospore

69 Asexual Sporulation Sporangiospores formed by cleavage of protoplasm in a multinucleate sporangium (Chytridiomycota, Zygomycota, Oomycota) Conidia develop directly from hyphae or from modified hyphal cells called conidiogenous cells (Ascomycota including Deuteromycetes, some Basidiomycota)

70 1. Sporangiospore Spore formed because cell protoplasm divide itself, formed small groups in sporangium pocket that placed on the tip of sporangiophore on hyphae has non septate. Ex/ Rhizopus sp. Mucor sp. Asexual spore formed within a sac (sporangium).

71 2. CONIDIOSPORE -Spore formed because the tips of hyphae split.
Unicellular or multicellular spore that is not enclosed in a sac. -Spore formed because the tips of hyphae split. -Conidia formed at the tip of hyphae. -Pillar hyphae called Conidiophore. Ex/ Penicillium sp. Aspergillus sp.

72 3. ARTHROSPORE Spore formed because a part of hyphae is broken & the wall thicken but not expand. ex/ Geotrichum Coccidioides Trichosporon

73 4. CLAMIDOSPORE Spore formed because part of hyphae expand & create thick wall. Rest phase Many found at old hyphae. ex/ Candida albicans Epidermophyton Thick-walled spore formed within a hyphal segment.

74 5. BLASTOSPORE Spore which created from budding on yeast cell & the bud not liberated from its mother ex/ Rhodotorula sp. Blastomyces dermatitidis

75 Sexual Sporulation 1. ASCOSPORE
One-cell spore formed inside a pocket called ascus ex/ Saccharomyces

76 2. BASIDIOSPORE Spore producted by basidia. Basidium exist on the tip of hyphae expanding that formed like vase/club ex/ Cryptococcus neoformans

77 3. ZYGOSPORE Big thick-walled spore that formed if the tip of
two swollen hyphae (gametangia) fuse (merged) ex/ Rhizopus Mucor

78 4. OOSPORE Spore that formed inside oogonium because
female gamet (oospher) fertilized by male gamet (antheredium)  oospore Inside each oogonium exist > 1 oospher

79 Question: What is the largest living thing on Earth?

80 No!

81 A Giant Fungus! Strange but True: The Largest Organism on Earth is a Fungus What is probably the largest living organism on earth has been discovered in the Malheur National Forest in eastern Oregon. A fungus living three feet underground is estimated to cover 2,200 acres. After testing samples from various locations, scientists say it is all one organism. Officially known as Armillaria ostoyae, or the honey mushroom, the fungus is 3.5 miles across and cover 2200 acres (takes up 1665 football fields). The small mushrooms visible above ground are only the tip of the iceberg. Experts estimate that the giant mushroom is at least 2400 years old, but could be 7200 years old. Aerial view of smaller forest patches infected by Armillaria in Montana 1 acre=4.046,86 m²= ~4 dönüm 2200 acre= m² 1 mil=1,6 km 3.5 mil= 5,4 km

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83 A Brief Summary

84 Cellulose cell walls, 2N hyphae Flagellated oospores from sporangia
Phylum Ex’s Characteristics Asexual Sexual Oomycota Mildew Spud blight Cellulose cell walls, 2N hyphae Flagellated oospores from sporangia Gametes fuse in gametangia creating oospores Zygomycota Rhizopus a dung fungus Chitin cell walls Coenocytic = hyphae lack crosswalls Unflagel. spores drop from sporangia Gametangia fuse to create zygospore Ascomycota Yeast, morels, truffles Conidia on conidophores Hyphae + & - fuse to create ascospores in ascus Basidiomycota Mushrooms Puffballs, rusts, smuts Cross walls in hyphae Asexual by way of Conidophores which produce conidiospores Sexual when hyphae fuse in BASIDIA to produce basidiospores Deuteromycota Penicillium, Athlete’s Foot fungus, Tomato Blight Similar to Basidio and Zygomy Asexual by conidia which produce conidophores Sexual repro Not known

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