TaxonomyTaxonomy

a classification of organisms into groups based on similarities of structure or origin etc.

KINGDOM CHARACTERISTIC EXAMPLE

     

Monera Prokaryocyte BacteriaActinomyces

Protista Eukaryocyte Protozoa

Fungi Eukaryocyte* Fungi

Plants Eukaryocyte PlantsMoss

Animals Eukaryocyte* ArthropodsMammals

Man

 

KINGDOM CHARACTERISTIC EXAMPLE

     

Monera Prokaryocyte BacteriaActinomyces

Protista Eukaryocyte Protozoa

Fungi Eukaryocyte* Fungi

Plants Eukaryocyte PlantsMoss

Animals Eukaryocyte* ArthropodsMammals

Man

 

Classification of FungiClassification of Fungi KingdomKingdom FungiFungi DivisionDivision -mycota-mycota SubdivisionSubdivision -mycotina-mycotina ClassClass -mycetae-mycetae SubclassSubclass -mycetes-mycetes OrderOrder -ales-ales FamilyFamily -aceae-aceae GenusGenus ---------------- SpeciesSpecies ----------------

Classification of FungiClassification of Fungi Four major division of fungi, base on th

e type of sexual spores (ascospore, basi diospore, zygospore, oospore), plus ano

ther group, which have no know sexual state.

– Chytridiomycota– Zygomycota– Ascomycota– Basidiomycota– Deuteromycota (Imperfect fungi)

Classification & Phylogeny

motile spores

zygosporangia

ascibasidia

Chytridiomycota – “chytridsChytridiomycota – “chytrids”” Simple fungiSimple fungi Produce motile spores Produce motile spores

- zoospores- zoospores Mostly saprobes and Mostly saprobes and

parasites in aquatic parasites in aquatic habitatshabitats

Could just as well be Could just as well be ProtistsProtists

Chytridium growing on spores

Chytriomyces growing on pine pollen

‘‘Chytrids’ are considered the earliest branch Chytrids’ are considered the earliest branch of the true fungi (Eumycota)of the true fungi (Eumycota)

Cell walls contain chitin and glucanCell walls contain chitin and glucan Only true fungi that produce motile, Only true fungi that produce motile,

flagellated zoosporesflagellated zoospores

– – Usually single, posterior whiplash typeUsually single, posterior whiplash type

– – Some species have multiple flagellaSome species have multiple flagella Zoospore ultrastructure is taxonomically Zoospore ultrastructure is taxonomically

important within this phylumimportant within this phylum Commonly found in soils or aquatic Commonly found in soils or aquatic

environments, chytrids have a significant environments, chytrids have a significant role in degrading organicsrole in degrading organics

A few are obligate intracellular parasites of A few are obligate intracellular parasites of plants, algae, and small animals (e.g., frogs)plants, algae, and small animals (e.g., frogs)

Very few economically important species Very few economically important species ((Synchytrium endobioticum Synchytrium endobioticum causes potato causes potato wart disease)wart disease)

More important (and fascinating) as More important (and fascinating) as biological models (e.g, biological models (e.g, Allomyces).Allomyces).

Zygomycota – “zygote fungiZygomycota – “zygote fungi””

Sexual Reproduction - Sexual Reproduction - zygosporangiazygosporangia

Asexual reprod. – common Asexual reprod. – common (sporangia – bags of (sporangia – bags of asexual spores)asexual spores)

Hyphae have no cross wallsHyphae have no cross walls Grow rapidlyGrow rapidly Decomposers, pathogens, Decomposers, pathogens,

and some form mycorrhizal and some form mycorrhizal associations with plantsassociations with plants

Rhizopus on strawberries

Rhinocerebral zygomycosis

Five features of Phylum ZygomycotaFive features of Phylum Zygomycota

– – Cell walls contain chitin, chitosan, and Cell walls contain chitin, chitosan, and polyglucuronic acidpolyglucuronic acid

– – Some members typically bear Some members typically bear multinucleate, coenocytic hyphae, i.e., multinucleate, coenocytic hyphae, i.e., without cross walls (septa; sing., septum)without cross walls (septa; sing., septum)

• • When present, septa are simple When present, septa are simple partitionspartitions

• • Some Orders have regular septations Some Orders have regular septations that are flared having a centrally plugged that are flared having a centrally plugged porepore

– – Produce zygospores (meiospore).Produce zygospores (meiospore).

– – Asexual spores (mitospores), termed Asexual spores (mitospores), termed sporangiospores, form through cytoplasmic sporangiospores, form through cytoplasmic cleavage within a sac-like structure termed a cleavage within a sac-like structure termed a sporangiumsporangium

– – Haploid genomeHaploid genome Importance of the zygomycetous fungiImportance of the zygomycetous fungi

– – Organic degraders/recyclersOrganic degraders/recyclers

– – Useful in foodstuffs/fermentationsUseful in foodstuffs/fermentations

– – Pathogens of insects/other animalsPathogens of insects/other animals Generalized life cycleGeneralized life cycle

– – Asexual stage (anamorphic; imperfect)Asexual stage (anamorphic; imperfect)

• • A thin-walled sac (sporangium) is walled A thin-walled sac (sporangium) is walled off at the tip and fills with cytoplasmoff at the tip and fills with cytoplasm

• • containing multiple nuclei (with collumella containing multiple nuclei (with collumella underneath sac)underneath sac)

• • Cytoplasmic cleavage and separation of Cytoplasmic cleavage and separation of nuclei into walled units produces nuclei into walled units produces sporangiosporessporangiospores

• • Thin sporangial wall (peridium) breaks Thin sporangial wall (peridium) breaks releasing sporangiosporesreleasing sporangiospores

• • Sporangiospores germinate to repeat the asexual Sporangiospores germinate to repeat the asexual life cyclelife cycle

The zygospore represents the teleomorphic The zygospore represents the teleomorphic phase (sexual; perfect form) of this phylumphase (sexual; perfect form) of this phylum

– – Results from the fusion of gametangia of Results from the fusion of gametangia of heterothallic (two different mating types; heterothallic (two different mating types; designated “+” and “-”) or homothallic (self designated “+” and “-”) or homothallic (self fertile) strainsfertile) strains

– – Acts as a thick-walled resting sporeActs as a thick-walled resting spore

• • Zygosporangium becomes thick walled Zygosporangium becomes thick walled to form the zygosporeto form the zygospore

• • Hyphae to the sides become empty Hyphae to the sides become empty appendages (suspensor cells)appendages (suspensor cells)

• • Zygospore often forms ornate Zygospore often forms ornate appendagesappendages

• • Zygospore is constitutively dormant for Zygospore is constitutively dormant for a time, but then germinates to produce a a time, but then germinates to produce a sporangium containing haploid sporangium containing haploid sporangiosporessporangiospores

Life cycle of Rhizopus

Asexual sporangium with spores inside

Sexual zygsporangium with one zygospore

Ascomycota – “sac fungiAscomycota – “sac fungi””

Sexual Reproduction – Sexual Reproduction – asci (sing. = ascus)asci (sing. = ascus)

Asex. Reprod. – Asex. Reprod. – commoncommon

Cup fungi, morels, Cup fungi, morels, trufflestruffles

Important plant Important plant parasites & saprobesparasites & saprobes

Yeast -Yeast - Saccharomyces Saccharomyces Decomposers, Decomposers,

pathogens, and found pathogens, and found in most lichensin most lichens

A cluster of asci with spores inside

Life cycle of AscomycetesLife cycle of Ascomycetes

Ascocarp

- Perithecium

- Apothecium

- Cleistothecium

Apothecium

Perithecium

Cleistothecium

Basidiomycota – “club fungiBasidiomycota – “club fungi”” Sexual Reproduction – Sexual Reproduction –

basidiabasidia Asexual reprod – not so Asexual reprod – not so

commoncommon Long-lived Long-lived dikaryoticdikaryotic

myceliamycelia Rusts & smuts –plant Rusts & smuts –plant

parasitesparasites Mushrooms, polypores, Mushrooms, polypores,

puffballs, boletes, bird’s puffballs, boletes, bird’s nest fungi nest fungi

Enzymes decompose Enzymes decompose wood, leaves, and other wood, leaves, and other organic materialsorganic materials

Decomposers, pathogens, Decomposers, pathogens, and some form and some form mycorrhizal associations mycorrhizal associations with plantswith plants

SEM of basidia and spores

Clamp connectionClamp connection

Life cycle of basidiomycetesLife cycle of basidiomycetes

Some fungi have more than Some fungi have more than one scientific name – Whyone scientific name – Why??

TeleomorphTeleomorph: the sexual reproductive : the sexual reproductive stage (morph), typically a fruiting body stage (morph), typically a fruiting body (e.g., (e.g., Morchella esculentaMorchella esculenta, , Agaricus Agaricus brunescensbrunescens). ).

AnamorphAnamorph: an asexual reproductive stage : an asexual reproductive stage (morph), often mold-like (e.g. (morph), often mold-like (e.g. Aspergillus Aspergillus flavusflavus, , Fusarium solaniFusarium solani). ).

HolomorphHolomorph: the whole fungus, including : the whole fungus, including all anamorphs and the teleomorph. all anamorphs and the teleomorph.

Deuteromycota – Form Phylum Deuteromycota – Form Phylum “Imperfect Fungi“Imperfect Fungi””

Fungi that seldom or never Fungi that seldom or never reproduce sexually.reproduce sexually.

Asexual reproduction by vegetative Asexual reproduction by vegetative growth and production of asexual growth and production of asexual spores common.spores common.

HUMAN-FUNGUS INTERACTIONSHUMAN-FUNGUS INTERACTIONS

Beneficial Effects of FungiBeneficial Effects of Fungi – Decomposition - nutrient and carbon recycling. Decomposition - nutrient and carbon recycling. – Biosynthetic factories. Can be used to produce drugs, Biosynthetic factories. Can be used to produce drugs,

antibiotics, alcohol, acids, food (e.g., fermented antibiotics, alcohol, acids, food (e.g., fermented products, mushrooms). products, mushrooms).

– Model organisms for biochemical and genetic studies. Model organisms for biochemical and genetic studies. Harmful Effects of FungiHarmful Effects of Fungi

– Destruction of food, lumber, paper, and cloth. Destruction of food, lumber, paper, and cloth. – Animal and human diseases, including allergies. Animal and human diseases, including allergies. – Toxins produced by poisonous mushrooms and within Toxins produced by poisonous mushrooms and within

food (e.g., grain, cheese, etc.). food (e.g., grain, cheese, etc.). – Plant diseases. Plant diseases.