KINGDOM KINGDOM FUNGIFUNGI

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CharacteristicsCharacteristics

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Eukaryotes Most are saprobes

(live on dead organisms)

Grow best in warm, moist environments

Mycology is the study of fungi

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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 BREAD MOLDMOLD

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Cell walls are made of chitin (complex polysaccharide)

Body is called the Thallus

Grow as microscopic tubes or filaments called hyphae

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Produce both sexual and asexual spores

Classified by their sexual reproductive structures

Spores come Spores come in various in various

shapesshapes66

Vegetative StructuresVegetative Structures

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TubularTubular shape ONEONE continuous cell Filled with

cytoplasm & nucleicytoplasm & nuclei MultinucleateMultinucleate Hard cell wall of

chitinchitin also in insect exoskeletons

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StolonsStolons – horizontal hyphae that connect groups of hyphae to each other

RhizoidsRhizoids – rootlike parts of hyphae that anchor the fungus

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STOLOSTOLONN

RHIZOIDSRHIZOIDS

Cross-walls called SEPTA may form compartments

Septa have pores for movement of cytoplasm

Form network called mycelia (non reproductive) that run through the thallus (reproductive body)

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ABSORPTIVE ABSORPTIVE HETEROTROPHHETEROTROPH

Fungi get carbon from organic sources Tips of Hyphae release enzymes Enzymatic breakdown of substrate Products diffuse back into hyphae

Digested material is then used by the hypha

Nucleus “directs” the digestive process

Hyphae grow from their tips Mycelium is an extensive,

feeding web of hyphae Mycelia are the ecologically

active bodies of fungi

This wall is rigid Only the tip wall is plastic and stretches

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REPRODUCTIVE STRUCTURESREPRODUCTIVE STRUCTURES

ASEXUAL & SEXUAL SPORESASEXUAL & SEXUAL SPORES

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REPRODUCTIONREPRODUCTION

Most fungi reproduce AsexuallyAsexually and SexuallySexually by spores

ASEXUAL reproduction is most most common common method & produces genetically identical genetically identical organisms

Fungi reproduce SEXUALLY when conditions are poor & nutrients conditions are poor & nutrients scarcescarce

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SPORESSPORES

Spores are an adaptationadaptation to life on land

Ensure that the species will species will disperse to new locationsdisperse to new locations

Each spore contains a reproductive reproductive cellcell that forms a new organism

NonmotileNonmotile Dispersed by windwind

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SEXUAL REPRODUCTIONSEXUAL REPRODUCTION Used when Used when

environmental environmental conditions are poor conditions are poor (lack of nutrients, (lack of nutrients, space, moisture…)space, moisture…)

No male or female fungiNo male or female fungi Some fungi show Some fungi show

dimorphismdimorphism May grow as May grow as MYCELIA MYCELIA

or aor a YEAST –LIKE YEAST –LIKE state (Filament at state (Filament at 2525ooC & Round at 37C & Round at 37ooC)C)

1717Dimorphic FungiDimorphic Fungi

SEXUAL REPRODUCTIONSEXUAL REPRODUCTION Haploid 1n hyphae 1n hyphae from 2 mating 2 mating

types (+ and -) FUSE types (+ and -) FUSE (Fertilization)(Fertilization) Forms aForms a hyphae with hyphae with 2 nuclei that 2 nuclei that

becomes a ZYGOTEbecomes a ZYGOTE The zygote divides to make a The zygote divides to make a

SPORESPORE

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++ --

SPORE SPORE FORMSFORMS

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THREE TYPES OF ASEXUAL THREE TYPES OF ASEXUAL REPRODUCTIONREPRODUCTION

FragmentationFragmentation – part of the mycelium becomes separated & begins a life of its own

BuddingBudding – a small cell forms & gets pinched off as it grows to full size Used by yeasts Used by yeasts

Asexual spores Asexual spores – production of – production of spores by a single myceliumspores by a single mycelium

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Spores may be Formed: Directly on hyphae Inside sporangia On Fruiting bodies

Amanita fruiting body Pilobolus sporangia

Penicillium hyphae

Fruiting Bodies Fruiting Bodies are modified hyphae that make asexualasexual spores

An upright stalk called the SporangiosphoreSporangiosphore supports the spore case or SporangiumSporangium

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Types of Types of Fruiting Fruiting Bodies:Bodies: BasidiaBasidia SporangiaSporangia AscusAscus

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BasidiaBasidia

SporangiaSporangia

myceliummycelium

Fruiting BodiesFruiting Bodies

Both are compose

d of hyphae

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Mycelia have a huge surface area More surface area aids digestion & absorption of food

mycelium

Germinating spore

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Evolution of FungiEvolution of Fungi

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Which of the following is most closely related to a mushroom (fungus)?

WHY?WHY?Recent DNA-Recent DNA-

based studies based studies show that fungi show that fungi are more similar are more similar to animals than to animals than to plantsto plants

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Evolution of the Evolution of the FungiFungi

Fungi are classified by their REPRODUCTIVE STRUCTURES REPRODUCTIVE STRUCTURES andand SPORESSPORES

The reproductive structures are: BASIDIA - BASIDIA - BASIDIOMYCOTABASIDIOMYCOTA SPORANGIA - SPORANGIA - ZYGOSPORANGIAZYGOSPORANGIA ASCUS - ASCUS - ASCOMYCOTAASCOMYCOTA

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Spores are made of:Spores are made of: Dehydrated cytoplasmDehydrated cytoplasm Protective coatProtective coat Haploid cellHaploid cell

Wind, animals, water, & insects Wind, animals, water, & insects spread sporesspread spores

Spores germinates when they Spores germinates when they land on a moist surface land on a moist surface (new (new hyphae form)hyphae form)

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ClassificatiClassification & on &

PhylogenyPhylogeny

motile spores

zygosporangia

ascibasidia

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Major Groups of FungiMajor Groups of Fungi

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MAJOR GROUPS OF FUNGIMAJOR GROUPS OF FUNGI

Within the past few years, several groups have been re-re-classified into classified into the protiststhe protists

Two of these groups are the slime molds slime molds and and water moldswater molds

SaprobesSaprobes Decomposers Molds, mushrooms, etc.

ParasitesParasites Harm host Rusts and smuts (attack plants)

MutualistsMutualists Both benefit Lichens Mycorrhizas

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MAJOR GROUPS OF FUNGIMAJOR GROUPS OF FUNGI

Basidiomycota Basidiomycota – – Club Fungi ZygomycotaZygomycota – – Bread Molds Chytridiomycota Chytridiomycota – – Chytrids Ascomycota Ascomycota – – Sac Fungi Lichens/Lichens/Mycorrhizas– –

Symbiosis (plant or algae & Fungi)

ZYGOMYCOTAZYGOMYCOTA

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Called the sporangiumfungi

Commonly called molds Also includes blights Hyphae have no cross

walls (aseptate) Grow rapidly Includes bread mold

Rhizopus stolonifer

Rhizopus on strawberries

Tomato BlightTomato Blight

Asexual reproductive structure called sporangiumsporangium atop sporangiospores sporangiospores make sporesspores

Rhizoids Rhizoids anchor the mold & release digestive enzymes & absorb food

StolonsStolons connect the fruiting bodies

SexualSexual spores are produced by conjugationconjugation when (+) hyphae and (-) hyphae fusehyphae fuse

Sexual spores are called ZYGOSPORESZYGOSPORES

Zygospores can endure harsh endure harsh environmentsenvironments until conditions improvezygosporezygospore

BASIDIOMYCOTABASIDIOMYCOTA

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Called Club fungi Includes:

MushroomsMushrooms ToadstoolsToadstools Bracket & Shelf fungiBracket & Shelf fungi PuffballsPuffballs StinkhornsStinkhorns Rusts and smutsRusts and smuts

Some are used as food (mushrooms)(mushrooms)

Others damage crops (rusts & (rusts & smuts) smuts)

Corn Corn SmutSmut

Soybean Soybean RustRust

Portobello Portobello MushroomsMushrooms

CHARACTERISTICS OF CLUB CHARACTERISTICS OF CLUB FUNGIFUNGI

SeldomSeldom reproduce asexually The visible mushroom is a fruiting bodyfruiting body BasidiocarpBasidiocarp (fruiting body) is made of a

stalk called the stipestipe and a flattened cap cap with gills called BasidiaBasidia underneath

BasidiosporesBasidiospores are found on basidia Annulus and VolvaAnnulus and Volvais a skirt-like ring

around some stipes VegetativeVegetative structures found below

ground: Mycelium4343

Fig 31.12

Nuclear fusion in basidium

Meiosis

Hyphal fusion of haploid myceliahaploid

mycelium

young basidia - the only diploid cells

mycelium and fruiting body are dikaryotic

N 2N N+N

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ASCOMYCOTAASCOMYCOTA

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Called Sac fungiSac fungi Includes Cup fungi, morels, truffles, Cup fungi, morels, truffles,

yeasts, yeasts, and mildew mildew May be plant parasites (Dutch elm (Dutch elm

disease and Chestnut blight)disease and Chestnut blight) Reproduce sexually & asexually Ascus Ascus - sac that makes ascosporesascospores in

sexual reproduction Specialized hyphae known as

Ascocarps Ascocarps contain the asci

Yeasts reproduce asexually by budding budding (buds break off to make more yeast cells)

AsexualAsexual spores called conidiaconidia form on the tips of special hyphae called conidiophoresconidiophores CONIDIACONIDIA

CONIDIA FORMATIONCONIDIA FORMATION

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YEASTS BUDDINGYEASTS BUDDING

SaccharomycesSaccharomyces

TrufflesTruffles and morelsmorels are good examples of edible ascomycetes

Penicillium mold Penicillium mold makes the antibiotic penicillin.

Some ascomycetes also gives flavor to flavor to certain cheeses.cheeses.

Saccharomyces Saccharomyces cerevesiae cerevesiae (yeast) is used to make bread rise and to ferment beer & wine.

CHYTRIDIOMYCOTACHYTRIDIOMYCOTA

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Called chytridschytrids Produce motile motile

spores (flagella)spores (flagella) Mostly saprobessaprobes

and parasitesparasites in aquatic habitats

Biodegrade and Biodegrade and recycle recycle nutrients

Chytrid that attacks Chytrid that attacks PotatoesPotatoes

MYCORRHIZAMYCORRHIZA

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MYCORRHIZASMYCORRHIZAS Fungus associated with plant associated with plant

rootsroots MutualismMutualism between:

FungusFungus (nutrient & water uptake for plant)

PlantPlant (carbohydrate for fungus) Extremely important ecologicallyExtremely important ecologically

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LICHENSLICHENS

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LICHENSLICHENS

Mutualism between: FungusFungus (structure) Algae or Algae or

cyanobacteria cyanobacteria (provides food)

Form a thallus (body) Foliose (leaf-like)Foliose (leaf-like) Fruticose (shrub-like)Fruticose (shrub-like) Crustose (Crust-like)Crustose (Crust-like)

LICHEN STRUCTURELICHEN STRUCTURE

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