The Fungus Among Us

The strange and fascinating world of our most visible decomposers

What we WON’T do:

• Learn to identify edible mushrooms

• Freak out because there are approximately 10,000 fungal spores in each cubic meter of air

• Panic because we have Pneumocystis carinii living in our lungs right now (yes, YOUR lungs)

What we WILL do:

• Learn about unique reproduction strategies

• Appreciate that fungi are essential for life on this planet

• Delight in all the ways that fungi make our lives richer

Characteristics of Fungi

• Eukaryotic heterotrophs– digestion is external

• Chitin in cell walls– same chemical as found in insect exoskeletons

• Dikaryotic stage (some)– cells fuse (plasmogamy) but nuclei don’t!– therefore cells are n+n instead of 2n

Terminology• -gamy = marriage or fusion

• -karyon = nucleus -plasm = gel inside cell

• -ploid = sets of chromosomes (1n, 2n)

• spore = 1n cell that can germinate into a fully functional 1n cell

myco = fungus

Functions• saprobes (decomposers)

– up to armpits in dead bodies without them– nutrient cycles come to a halt (carbon, nitrogen,

etc.)

• parasites/pathogens– you name it, including other fungi

• mutualists– you name it– especially important: plants (~ 90% of all plants

MUST have fungal associations)

Ectomycorrhizae vs. Arbuscular mycorrhizae

Unicellular fungi = yeast

Multicellular: functional unit = hypha

mushroom = fruiting body

ONLY fungi with motile cells

Chytrids

http://frogmatters.wordpress.com/2008/03/

http://www.environment.nsw.gov.au/animals/FrogChytridFungus.htm

Chytrid infection of frogs has caused extinction of several species across the world.

Ease of global travel has exacerbated the problem.

Glomeromycota: ONLY reproduce asexually, NONE are unicellular

EXTREMELY important function: arbuscular mycorrhizae

from: http://www.google.com/imgres?imgurl=http://www.nature.com/ncomms/journal/v1/n4/images_article/ncomms1046-f4.jpg&imgrefurl=http://www.nature.com/ncomms/journal/v1/n4/full/ncomms1046.html&usg=__7YegfK1Kf9F35TIwzcySA-_ewp0=&h=411&w=600&sz=80&hl=en&start=21&sig2=8ks-42yCpXd5mTIoNyp4YA&zoom=1&tbnid=eVz-gQfOr2MucM:&tbnh=112&tbnw=163&ei=pending&prev=/images%3Fq%3Dglomerulomycete%26hl%3Den%26biw%3D1276%26bih%3D558%26gbv%3D2%26tbs%3Disch:10%2C503&itbs=1&iact=hc&vpx=829&vpy=179&dur=2964&hovh=186&hovw=271&tx=129&ty=120&oei=2E6WTPvYIc6dnwel0MyeBw&esq=2&page=2&ndsp=22&ved=1t:429,r:12,s:21&biw=1276&bih=558

Glomeromycota

http://life8eiml.sinauer.com/Animations/Chapter30/Animation-30-01.swf

WEIRD!

aka Cup Fungi

Saccharomyces cerevisiae favorite ‘cup’ fungus = Brewer’s & Baker’s yeast!!

Penicilium varieties responsible for Roquefort cheese and antibiotics!

http://americanmushrooms.com/coolest.htm

Mushroom Structure

http://www.google.com/imgres?imgurl=http://fungalguide.landcareresearch.co.nz/Images/MushroomDiagram.jpg&imgrefurl=http://fungalguide.landcareresearch.co.nz/WebForms/FG_About.aspx&usg=__MPTyhWk_-4gq6NXoTEPNv879uFo=&h=490&w=500&sz=50&hl=en&start=0&sig2=LQ_ilJDUBLdMLQWzxs_WHA&zoom=1&tbnid=JVlyrP5HGZ2xLM:&tbnh=132&tbnw=135&ei=dl-WTJi1HIe2nAelxeWlBw&prev=/images%3Fq%3Dmushroom%2Bstructure%26hl%3Den%26biw%3D1276%26bih%3D558%26gbv%3D2%26tbs%3Disch:1&itbs=1&iact=hc&vpx=1006&vpy=60&dur=187&hovh=222&hovw=227&tx=133&ty=132&oei=dl-WTJi1HIe2nAelxeWlBw&esq=1&page=1&ndsp=18&ved=1t:429,r:5,s:0

3 feet in length, ~20 lbs!http://news.bbc.co.uk/2/hi/uk_news/scotland/3839363.stm http://www.youtube.com/watch?v=EF65xGRNfwo

http://healthyhomegardening.com/Most_Viewed_Pages.php?m1=12

http://www.youtube.com/watch?v=GScyw3ammmk

http://www.youtube.com/watch?v=e1E48_W0DS4

http://www.youtube.com/watch?v=q7Qem8OloIY&feature=related

Common smut (Ustilago maydis) on an ear of corn.

Deuteromycete Pneumocystis carinii in human sputum.

Penicillium sp. growing on agar.