Mycology Exam 1

Monokaryon

one nucleus per hyphal compartment

Dikaryon

2 nuclei per hyphal compartment

Organelles

Typical eukaryotic assemblage with Golgi equivalents and microbodies

Golgi equivalents

single fold golgi

Microbodies

function in fatty acid degradation and nitrogen metabolism

Spitzenkörper

aggregation of vesicles associated with growing hyphal tips

Spore

-minute propagative unit that functions as a seed but doesn't contain a pre-formed embryo

Heterotrophic

Organisms that obtain their nutrients or food from consuming other organisms.

Saprobes

organisms that obtain food from decaying organic matter

Secretive/Absorptive nutrition

1) Hydrolytic and oxidative enzymes secreted
2) Enzymes degrade substances in the environment
3) Degraded nutrients are absorbed into cell via endocytosis

Cell wall of Fungi

well defined complex matrix of polysaccharides and proteins and contains chitin and one of the major components are glucans and components can change throughout life cycle and between species

Glucans

polymers of glucose

AAA Lysine Biosynthesis

Can make lysine in their bodies

Hypha

basic cellular unit of filamentous fungi and they may be septate or coenocytic (aseptate)

Septate hyphae

contain cross-walls

Coenocytic hyphae

hyphae that contain no septa and appear as long, continuous cells with many nuclei

Mycelium

densely branched network of the hyphae of a fungus

Sporocarp

any complex fungal structure that contains or bears spores (where tissue differentiation happens)

How to classify diversity?

Ecology, Morphology, Phylogenetics

Challenges with classifying with morphology

Difficult to differentiate between homology and homoplasy

Homology

similarity due to common ancestry

Homoplasy

similarity of characters that evolved independently (product of conversion evolution)

Phenetics

classification of organisms based on phenotypic traits

Phylogenetics

The study of evolutionary relationships among organisms

Zoosprangium

spore case

Oomycetes ("Water molds")

~700 species
-Mycelial (coenocytic)
-Zoosporangium
-Zoospore with two anterior, heterokont flagella (unequal length)
-no sporocarp production
-aquatic and terrestrial

Slime molds

~850 species
-Dictyostelia = cellular slime molds (have septate hyphae)
-Myxogastria = plasmodial slime molds (have coenocytic hyphae)
-no cell wall
-terrestrial

Dictyostelia

cellular slime molds (have septate hyphae)

Myxogastria

plasmodial slime molds (have coenocytic hyphae)

Cryptomycota

~30 species
-unicellular
-zoospore OR polar filament
-ALL intracellular parasites
-Highly reduced

Microsporidia

~1500 species
-unicellular
-zoospore OR polar filament
-ALL intracellular parasites
-Highly reduced

Chytridiomycota

~700 species
- unicellular to mycelial (coenocytic)
- zoospore with single posterior flagellum
- no sporocarp production
- aquatic and terrestrial

Blastocladiomycota

~200 spp.
- Mycelial (coenocytic)
- Zoospores w/single posterior flagellum
- Complex life cycles
- Aquatic or terrestrial

Zoopagomycota

~400 species
- Mycelium (coenocytic)
- Most pathogens of animals or mycoparasites
- Sexual reproduction via Zygosporangium

Mucoromycota

~600 species
- Coenocytic mycelium
- Sexual reproduction viz zygosporangia -> zygospores
- Many saprobes and soil fungi
- Arbuscular mycorrhizae

Basidiomycota

~25,000 species
- Septate mycelium
- Clamp connections
- Dikaryotic mycelium
- Production of basidiospores on a basidium
- Production of complex sporocarps

Ascomycota

~35,000 species
- Septate mycelia
- Monokaryotic, Haploid mycelia
- Production of ascospores in an ascus
- Production of complex sporocarps
- Often dominant asexual reproduction

Diversity of Basidiomycota

~25,000 described species

Growth forms of Basidiomycota

Filamentous to yeast

Reproductive structures of Basidiomycota

Lacking sporocarps to highly developed fruiting bodies

Nutritional Modes of Basidiomycota

Saprobic: Eating of dead organic matter
Biotrophic: parasitic
Necrotrophic: parasite that kills its host and eats the dead matter

Basidiomycota Symbiosis

Mycorrhizae, insect symbionts, plant & animal pathogens, etc

Dikaryon

2 separate but compatible nuclei in each cell or compartment (unique to Basidiomycota and Ascomycota)

Synapomorphy

a characteristic present in an ancestral species and shared exclusively (in more or less modified form) by its evolutionary descendants

Basidium

-Synapomorphy of Basidiomycota
- Specialized hyphal tip
- Site of meiosis
- Products of meiosis = basidiospores
- Usually located in specialized regions or tissues (e.g. gills or pores)

Stages of Basidium

1) Probasidium = (n+n to 2n) - site of karyogamy
2) metabasidium = (2n to n+n+n+n) - site of meiosis
3) mature basidium - basidiospores produced exogenously

Sterigma(ta)

Section between basidium and basidiospores

Holobasidium

aseptate basidium

Phragmobasidium

basidium with septations

Basidiospores

- one to several haploid nuclei per spore (1-2 most common)
- 2-8 spores per basidium (4 most common)

Ballistospores

forcibly ejected basidiospores

Statismospores

passively ejected basidiospores that are symmetrically situated on sterigmata

Amyloid spores

blue-black in iodine

Dextrinoid spores

red-brown in iodine

Cystidium

Sterile cell occurring amongst basidia along the hymenium

Hymenium

Fertile portion of mushrooms where spores are produced

Clamp connections

hyphal extension in opposite orientation of growth and function in maintaining the Dikaryon in Basidiomycota

Basidiomycota Life Cycle

1) Sporocarp (n+n)
2) Gilled Hymenophore (n+n)
3) Gill (n+n)
4) Basidium (n+n -> 2n -> n+n+n+n)
5) Basidiospore (n)
6) Monokaryon (n)
7) Fusion of monokaryons (n -> n+n)
8) Clamp connections (n+n)
9) Dikaryon (n+n)
10) Mycelium (n+n)
11) Sporocarp primordia (n+n)

Hymenophore

hymenium-bearing structure of a fungal fruiting body

Basidioma(ta)

formal term used to designate to basidiocarp or sporocarp of basidiomycetes (fruiting body)

Pileus

cap or upper surface of basidiomata

Stipe

the stalk of a mushroom (can be central, eccentric, lateral, absent and solid, hollow, or stuffed)

Gleba

enclosed spore mass of gasteromycetes

Peridium

outer tissue that encloses gleba of gasteromycetes, homologous to pileus of mushroom, one to many layers

Veils

-Universal veil (volva and scales)
-Partial veil (annulus/skirt)

Pucciniomycotina

-Rusts, marine yeasts
-teliospore with phragmobasidium
-simple septa
-septal pore occlusions

Ustilaginomycotina

-Smut, bunts, yeasts
-teliospore with phragmobasidium or holobasidium
-"smut septa"
- septal pore cap

Agaricomycotina

-Mushrooms, jelly fungi, conks, coral, crusts, puffballs
- holobasidium (main) or phragmobasidium
- Dolipore septa
- Perforated and nonperforated septal pore cap

Resupinate

lying flat on the substratum without a stalk or well defined cap

Light spore print

white, yellow, pink, lilac

Dark spore print

black, purple, brown, red, rust, green