intro to fungi presentation - fall 2008
DESCRIPTION
Different species of fungi FungiTRANSCRIPT
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
1/36
Kingdom Fungi
The characteristics
of fungi The evolution of
the fungi
Fungalclassification
Fungal life cycles
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
2/36
The Characteristics of Fungi Body form
* unicellular* filamentous (tube-like
strands called hypha(singular) or hyphae(plural)
* mycelium = aggregateof hyphae
* sclerotium = hardenedmass of mycelium thatgenerally serves as an
overwintering stage.* multicellular, such as
mycelial cords,rhizomorphs, and fruit
bodies (mushrooms)
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
3/36
mycelium
fruiting bodies
both arecomposed
of hyphae
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
4/36
The Characteristics of Fungi
Heterotrophy - 'other food'* Saprophytes or saprobes - feed on dead
tissues or organic waste (decomposers)
* Symbionts - mutually beneficialrelationship between a fungus andanother organism
* Parasites - feeding on living tissue of a
host.
Parasites that cause disease are calledpathogens.
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
5/36
Heterotrophic by Absorption
Fungi get carbon from organic sources Hyphal tips release enzymes
Enzymatic breakdown of substrate
Products diffuse back into hyphae
Product diffuses back
into hypha and is used
Nucleus hangs back
and directs
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
6/36
Hyphae
Tubular
Hard wall of chitin
Crosswalls mayform compartments
( cells)
Multinucleate
Grow at tips
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
7/36
Hyphal growth
Hyphae grow from their tips Mycelium = extensive, feeding web of hyphae
Mycelia are the ecologically active bodies offungi
This wall is rigid Only the tip wall is plastic and stretches
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
8/36
Modifications of hyphae
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
9/36
Fungi as Saprobes andDecomposers
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
10/36
Fungi as Symbionts (Mutualism)
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
11/36
Mycorrhizae
Fungus roots Mutualism between:* Fungus (nutrient & water uptake for plant)
* Plant (carbohydrate for fungus)
Several kinds* Zygomycotahyphae invade root cells
* Ascomycota & Basidiomycotahyphae invade root but
dont penetrate cells
Extremely important ecological role of fungi!
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
12/36
Ectomycorrhizae
Russulamushroom
mycorrhizas on
Western
Hemlock root
Fungal hyphae
around root and
between cells
Mycorrhiza cross sections
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
13/36
Lichens
Mutualism between* Fungusstructure* Alga or cyanobacterium
provides food
Three main types of lichens:* Crustose lichens form flat
crusty plates.
* Foliose lichens are leafy inappearance, although lobed or
branched structures are not true
leaves.* Fruticose lichens are even more
finely branched and may hangdown like beards from branchesor grow up from the ground liketiny shrubs.
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
14/36
Lichen internal structure
Lobaria
Lichens are natures biological monitors
of pollution and air quality
Thalli act like sponges
Some species more sensitive to
pollution
Which species are present can
indicate air quality
Most resistant species can also be
analyzed for pollutants, including
bioaccumulation of heavy metals and
radioactive isotopes
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
15/36
Fungi as Parasites & Pathogens
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
16/36
Fungi are Spore-ific!!!
Spores - asexual (product ofmitosis) or sexual (product ofmeiosis) in origin.
Purpose of Spores
* Allows the fungus to moveto new food source.
* Resistant stage - allowsfungus to survive periods ofadversity.
* Means of introducing newgenetic combinations into a
population
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
17/36
Reproduce by spores Spores are reproductive cells
* Sexual (meiotic in origin)* Asexual (mitotic in origin)
Formed:* Directly on hyphae
* Inside sporangia* Fruiting bodies
Amanita fruiting body
Pilobolus sporangia
Penicillium hyphae
with conidia
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
18/36
Hyphal growth from spore
mycelium
germinating
spore
Mycelia have a huge surface area
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
19/36
The Characteristics of Fungi
Fungus is often hidden from view. It growsthrough its food source (substratum),
excretes extracellular digestive enzymes,and absorbs dissolved food.
Indeterminate clonal growth.
Vegetative phase of fungus is generallysedentary.
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
20/36
The Characteristics of Fungi
Cell wall present, composed of cellulose and/or chitin. Food storage - generally in the form of lipids and glycogen. Eukaryotes - true nucleus and other organelles present.
All fungi require water and oxygen (no obligate anaerobes). Fungi grow in almost every habitat imaginable, as long as there
is some type of organic matter present and the environment isnot too extreme.
Diverse group, number of described species is somewherebetween 69,000 to 100,000 (estimated 1.5 million species total).
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
21/36
Generalized Life Cycle of a Fungus
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
22/36
Evolution of the fungi
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
23/36
Classification
& Phylogeny
motile spores
zygosporangia
ascibasidia
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
24/36
Chytridiomycotachytrids Simple fungi
Produce motile spores -zoospores
Mostly saprobes and
parasites in aquatic habitats Could just as well be
Protists Chytridium growing on spores
Chytriomyces growing on pine pollen
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
25/36
Zygomycotazygote fungi
Sexual Reproduction -zygosporangia
Asexual reprod.common
(sporangiabags of asexualspores)
Hyphae have no cross walls Grow rapidly
Decomposers, pathogens, andsome form mycorrhizalassociations with plants
Rhizopus on strawberries
Rhinocerebral zygomycosis
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
26/36
Life cycle ofRhizopus
Asexual sporangium
with spores inside
Sexual zygsporangium
with one zygospore
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
27/36
Ascomycotasac fungi
Sexual Reproductionasci(sing. = ascus)
Asex. Reprod.common
Cup fungi, morels, truffles
Important plant parasites &saprobes
Yeast - Saccharomyces Decomposers, pathogens,and found in most lichens
A cluster of asci with spores inside
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
28/36
Sac fungi diversity
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
29/36
Basidiomycotaclub fungi
Sexual Reproductionbasidia Asexual reprodnot socommon
Long-lived dikaryotic mycelia Rusts & smutsplant parasites Mushrooms, polypores,
puffballs, boletes, birds nestfungi
Enzymes decompose wood,leaves, and other organic
materials Decomposers, pathogens, and
some form mycorrhizalassociations with plants SEM of basidia and spores
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
30/36
Mushroom
Life Cycle
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
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
31/36
Bioluminescence in Mycena
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
32/36
Some fungi have more than
one scientific name Why? Teleomorph: the sexual reproductive stage
(morph), typically a fruiting body (e.g.,Morchellaesculenta,Agaricus brunescens).
Anamorph: an asexual reproductive stage(morph), often mold-like (e.g.Aspergillus flavus,
Fusarium solani). When a single fungus producesmultiple morphologically distinct anamorphs, they
are called synanamorphs.
Holomorph: the whole fungus, including allanamorphs and the teleomorph.
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
33/36
Deuteromycota Form Phylum
Imperfect Fungi Fungi that seldom or never reproduce
sexually.
Asexual reproduction by vegetative growthand production of asexual spores common.
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
34/36
Yeasts
Single celled fungi
Adapted to liquids* Plant saps
* Water films* Moist animal tissues
CandidaSaccharomyces
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
35/36
Molds Rapidly growth Asexual spores Many human importances
* Food spoilage
* Food products
* Antibiotics, etc.
Noble Rot -Botrytis
-
7/15/2019 Intro to Fungi Presentation - Fall 2008
36/36
HUMAN-FUNGUS INTERACTIONS
Beneficial Effects of Fungi* Decomposition - nutrient and carbon recycling.
* Biosynthetic factories. Can be used to produce drugs, antibiotics,
alcohol, acids, food (e.g., fermented products, mushrooms).* Model organisms for biochemical and genetic studies.
Harmful Effects of Fungi* Destruction of food, lumber, paper, and cloth.
* Animal and human diseases, including allergies.
* Toxins produced by poisonous mushrooms and within food (e.g.,grain, cheese, etc.).
* Plant diseases.