FungiFungi

Unit 8- Chapter 31Unit 8- Chapter 31

What is a Fungi?What is a Fungi?

Usually multicellularUsually multicellular Above ground structures (mushrooms)Above ground structures (mushrooms) Breakdown organic material and Breakdown organic material and

recycle nutrientsrecycle nutrients Tiny fraction causes diseaseTiny fraction causes disease Plant roots depend on them to help Plant roots depend on them to help

with nutrient absorbtion (symbiotic with nutrient absorbtion (symbiotic relationship)relationship)

Nutrition and LifestyleNutrition and Lifestyle HeterotrophsHeterotrophs Do not ingest food Do not ingest food Secrete enzymes (Secrete enzymes (exoenzymes) exoenzymes) into their into their

surroundings, which break down surroundings, which break down complex molecules for the fungi to complex molecules for the fungi to absorb.absorb.

Some species are:Some species are: Decomposers:Decomposers: break down non living material (logs, break down non living material (logs,

wastes from animals, animal corpseswastes from animals, animal corpses Parasites:Parasites: absorb nutrients from host cells absorb nutrients from host cells Mutualistic symbionts:Mutualistic symbionts: absorb nutrients from host absorb nutrients from host

cell but the host cell isn’t hurt but rather benefits cell but the host cell isn’t hurt but rather benefits from the fungifrom the fungi

Body StructureBody Structure Single cell fungi = Single cell fungi =

yeastyeast Most are multicellularMost are multicellular HyphaeHyphae: A filament : A filament

that collectively that collectively makes up the body of makes up the body of a fungus.a fungus.

Chitin:Chitin: a strong but a strong but flexible flexible polysaccharide that polysaccharide that makes up the cell wall makes up the cell wall of fungi.of fungi.

Mycelium:Mycelium: the the branched network of branched network of hyphae that allows for hyphae that allows for feedingfeeding

Specialized HyphaeSpecialized Hyphae Septa:Septa: pores large pores large

enough for enough for organelles to flow organelles to flow from cell to cellfrom cell to cell

Coenocytic:Coenocytic: lack lack pores, continuous pores, continuous cytoplasm with cytoplasm with many nuclei.many nuclei.

Haustoria:Haustoria: enables enables penetrating of a host penetrating of a host cells tissue.cells tissue.

Mycorrhizae:Mycorrhizae: symbiotic relationship symbiotic relationship with plant roots.with plant roots.

Sexual ReproductionSexual Reproduction Hyphae from 2 different mycelia release Hyphae from 2 different mycelia release

sexual signaling molecules sexual signaling molecules ((pheromones)pheromones) Both Hyphae extend toward the source of Both Hyphae extend toward the source of

pheromones and fuse together.pheromones and fuse together. ““Compatibility Test” prevents haphae from Compatibility Test” prevents haphae from

fusing with hyphae from the same mycelium.fusing with hyphae from the same mycelium. Union of cytoplasm Union of cytoplasm (plasmogamy)(plasmogamy) Hours, days, centuries later the haploid Hours, days, centuries later the haploid

nuclei from each parent fuse together = nuclei from each parent fuse together = diploid cell diploid cell (karyogamy) (karyogamy)

MeiosisMeiosis occurs and restores cells back to occurs and restores cells back to haploid form producing sporeshaploid form producing spores

Asexual ReproductionAsexual Reproduction

Clones are produced by mitotic Clones are produced by mitotic production of sporesproduction of spores

Spores are spread through air, wind, Spores are spread through air, wind, waterwater

Molds (kitchen products) produce Molds (kitchen products) produce sporesspores

Yeast (moist habitats) simple cell Yeast (moist habitats) simple cell divisiondivision

Fungal Fungal PhylogenyPhylogeny

Phylum ChytridiomycotaPhylum Chytridiomycota Aka ChytridsAka Chytrids Earliest of all fungiEarliest of all fungi Unique flagellated spores Unique flagellated spores (zoospores)(zoospores) Either decomposers or parasitesEither decomposers or parasites

Phylum ZygomycetesPhylum Zygomycetes Fast growing moldsFast growing molds Aka Zygote FungiAka Zygote Fungi Some are parasites or Some are parasites or

commensal symbionts (one commensal symbionts (one benefits)benefits)

Coenocytic hyphaeCoenocytic hyphae Parasites = MycrosporidiaParasites = Mycrosporidia

Phylum GlomeromycotaPhylum Glomeromycota

GlomeromycetesGlomeromycetes Form endomycorrhizae with plant Form endomycorrhizae with plant

rootsroots Hyphae branch into treelike Hyphae branch into treelike

structures structures

Phylum Phylum AscomycetesAscomycetes

Production of sexual spores Production of sexual spores (asci)(asci) Aka Sac FungiAka Sac Fungi Fruit bodies Fruit bodies (ascocarps)(ascocarps) Decomposers of plantsDecomposers of plants Symbiotic relationships with plant Symbiotic relationships with plant

roots and green algae (lichen)roots and green algae (lichen) Asexual reproduction: Produce Asexual reproduction: Produce

asexual spores asexual spores (conidia) (conidia) where where the spores are released into the the spores are released into the wind and attach to a hyphaewind and attach to a hyphae

Sexual reproduction: Fusion of 2 Sexual reproduction: Fusion of 2 different mating types, asci different mating types, asci produces ascospores which are produces ascospores which are later released by ascocarp.later released by ascocarp.

Phylum BasidiomycotaPhylum Basidiomycota BasidiomycetesBasidiomycetes Mushrooms, shelf fungi, aka club Mushrooms, shelf fungi, aka club

fungifungi Some molds and parasites (rust Some molds and parasites (rust

and smuts)and smuts) Decomposers of wood and plant Decomposers of wood and plant

materialmaterial Sexual reproductionSexual reproduction Fruiting bodies Fruiting bodies (basidiocarps) (basidiocarps)

ex: mushroomex: mushroom Mushroom cap releases the Mushroom cap releases the

basidiosporesbasidiospores Asexual reproduction is less Asexual reproduction is less

commoncommon

Impact of Impact of FungiFungi

Decomposers:Decomposers:- Plants Plants

(cellulose)(cellulose)- Keep ecosystems Keep ecosystems

stocked with stocked with inorganic inorganic nutrientsnutrients

- Balance carbon, Balance carbon, nitrogen, and nitrogen, and other essential other essential elementselements

- recyclerecycle

Symbionts:Symbionts:1. Mycorrhizae- relationship with1. Mycorrhizae- relationship withplant roots plant roots - Helps absorb nutrients that root- Helps absorb nutrients that rootcouldn’t normally get on its own.couldn’t normally get on its own.

2. Fungus/Animal Symbiosis-2. Fungus/Animal Symbiosis-breakbreak

down plant material in the guts ofdown plant material in the guts ofanimals. animals. -Ants take leaves to fungi so they-Ants take leaves to fungi so theycan break it down to a material incan break it down to a material inwhich the ants can digest.which the ants can digest.

3. Lichens- surface hugging 3. Lichens- surface hugging carpetcarpet

found growing on rocks, trees,found growing on rocks, trees,roofs, etc.roofs, etc.-fungi + green algae or-fungi + green algae orcyanobacteriacyanobacteria-”dual organism”-”dual organism”-sensitive to air pollution-sensitive to air pollution

Pathogens: -About 30% (mostly in plants)

-Affect agriculture

-When infected in animal/humans (mycosis)

-Ringworm

-Athletes foot

-Black mold

Practical use of FungiPractical use of Fungi

Mushroom for foodMushroom for food Fungi is used to ripen some cheesesFungi is used to ripen some cheeses Fungi are used to produce citric acid Fungi are used to produce citric acid

in soft drinksin soft drinks Yeast are used for alcoholic beveragesYeast are used for alcoholic beverages Antibiotics for bacterial infections Antibiotics for bacterial infections

(penicillin)(penicillin) Medical researchMedical research