- multiple origins of multicellularity

Green Algae - Chlorophyta:

Fungi:

Chapter 14

heterokonts

Oomycetes - Oomycota:

- heterotrophs - unicellular or filamentous - reproduction: - asexual: zoospores - sexual: oogonium, antheridium, oospores - habitats: - marine - aquatic - pathogens: - damping-off - potato blight - downy mildew in grapes

Encysted zoospores above empty sporangium

Oogonium with antheridium

Oomycota: Saprolegnia

Distinguishing the sexes in sexual reproduction:

- isogamy - anisogamy - oogamy

Questions generated by studying life cycles:

Why do Sex?

What is Sex anyway??

fungi

Myxomycota: Plasmodial slime molds!

- plasmodium - naked multinucleate protoplasm - heterotrophic - sexual reproduction present - sporangia or similar fuctioning structures produced - spores - the product of meiosis - sclerotium - dried encysted stage

Myxomycota:

Dictyosteliomycota or Acrasiomycota - Cellular Slime Molds - mostly exist as free myxamoebae - feed on bacteria by phagocytosis - pseudoplasmodium (slug) - aggregates of myxamoebae for reproduction - sexual reproduction - slug produces sporangium - stalk cells with cellulose walls -  asexual reproduction -  walled zygotes = macrocysts

Chytrids - Chytridomycota:

- only fungal group with motile cells somewhere in the life cycle - saprophytic or parasitic - unicellular to multicellular & filamentous - cysts - main body (in many) - rhizoids - root-like haustorium

Chytridiomycota Allomyces: -more extensive mycelium

gametangia

sporangia

Sporic Life Cycle

anisogamy

Zygomycota:

- nonmotile cells only - multicellular filamentous - hyphae coenocytic - mycelium & hyphae - asexual reproduction by sporangia & spores - borne on stalks sporangiophores

Pilobolus

Rhizopus

Zygomycota: Rhizopus stolonifer

stolon

zygosporangium

Zygotic Life Cycle

Mycorrhizae:

- an intimate nutritional association between fungi & plants

Mycorrhizae: - their effect on growth

without with

Mycorrhizae:

At least two kinds: - Ectomycorrhizae - found in many conifers, birches, oaks, orchids

hyphae of fungus are mostly exterior

- Endomycorrhizae:

- hyphae invade cells of host & form arbuscles - presumed site of nutrient/energy exchange - vessicles - storage? - VAM fungi - zygomycetes

vessicle

arbuscle

arbuscles

Point of penetration

VAM fungi:

- An obligate symbiote for the origin of higher land plants? (Pirozynski & Malloch 1970’s)

Ascomycota - Ascomycetes: - cup fungi, truffles, morels - powdery mildews, diseases - blue, green, brown molds - yeasts

Ascomycota: - mycelium - non- motile - septate hyphae

septum with septal pore

Ascomycota: - sexual reproduction: - formation of asci with ascospores

- containment of ascospores useful in genetic mapping of genetic recombination

meiosis (mitosis)

recombinants in

non-recombinants vs

Neurospora & Sordaria

Ascomycota: - types of ascomata (singl. ascoma): - cleistothecia, perithecia, apothecia

Ascomycota: - perithecia & cleistothecia perithecium

cleistothecia

asci

hymenium

Ascomycota: - apothecia, hymenium

Ascomycota: - asexual reproductive phase - conidia

conidiophores

Ascomycota:

Mycelium - the vegetative body

Life cycle involving dikaryon phase

Ascomycota: - Sexual cycle: ascogonium, antheridium - Ascogenous hyphae - dikaryotic

ascogonium

antheridium

homothallic (self-fertile) or heterothallic (more than one mating strain) mycelium strains (red or black)

dikaryotic hyphae

Ascomycota: - Ergot on rye -  St. Anthony s Fire & LSD -  drugs for migrane headaches

Basidiomycota: - mushrooms & toadstools - rusts, smuts, - plant & animal diseases

Basidiomycota: - mycelium - Probably the largest and oldest organisms on Earth

Basidiomycota: - dikaryon dominant phase - septate hyphae with dolipore septum - clamp connections

clamp connection:

Dolipore septum

Basidiomycota: - fruiting bodies (basidiomata) - base, volva (base cup), stipe (stalk), pileus (cap), hymenium (gills)

Basidiomycota:

- basidia (singl. basidium) with: 4 sterigmata (stalks) 4 basidiospores

spore print

Basidiomycota:

Basidiomycota: - boletes & bracket fungi

Basidiomycota: - coral fungi

Basidiomycota: - puff balls, earth stars

Basidiomycota: - stinkhorns - bird s nest fungi

splash cup

Basidiomycota: - poisonous mushrooms: - death or destroying angels Amanita - magic mushroom Amanita muscaria - Psilocybe, Teonancatl - many others

Basidiomycota: - rusts & smuts

Puccinia graminis - wheat rust

Early Spring

haploid mycelium

Puccinia graminis - wheat rust

Spring

dikaryon phase

in Barberry

Puccinia graminis - wheat rust

Spring

dikaryon phase on wheat

Puccinia graminis - wheat rust Summer

vegetative reinfection of wheat

dikaryon phase on wheat

Puccinia graminis - wheat rust

Fall

Summer

Winter

Next Spring

Lichens - An asymmetric symbiotic relationship: - photobiont (green alga and/or cyanobacteria) - mycobiont (ascomycete or basidiomycete) - ascomata & soredia (singl. soredium)

Lichen:

Lichen: - photobiont-mycobiont relationship

Lichens: - crustose, & foliose forms

Lichens: - fruticose forms

Endolithic lichens:

Yeast, Penicillium, Agaricus bisporus

Uses of fungi:

Fungal predators!