Date post: | 15-Jan-2017 |
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FUNGI
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MORE!
C H A R A C T E R I S T I CS
STRUCTURE
bigger than a blue whale?
really???
REPRODUCTION
&EVOLUTIO
N
NOT FOR
THE…
squeamish!!!
TOUR FUNGI HALL TO LEARN MORE!
(don’t be afraid to click )
ECOLOGY
CHARACTERISTICS OF FUNGI
• eukaryotic • heterotrophic – secrete enzymes into food
and absorb digested materials through cell walls– most are saprophytic – absorb organic
materials from dead organisms, “nature’s recycler”
• many are microscopicBACK TO FUNGI HALL
STRUCTURE OF FUNGI• made up of hyphae (filaments), collectively
called mycelium
mycelium
• cell walls contain chitin (also found in insect and crustacean exoskeletons)– plant cell walls contain ???– eubacteria cell walls contain ???
CONTINUED
CELLULOSE!
PEPTIDOGLYCAN!
STRUCTURE OF FUNGI• cells can be coenocytic – have many nuclei or
have separated by septa – “walls”• range in size from microscopic (yeast) to the
largest organism in the world (Armillaria – 3.1 mi2)• some are dimorphic – can change form based on
environmental conditions, can grow as mycelium in soil or as unicellular organisms in humans (Histoplasma)
BACK TO FUNGI HALL
REPRODUCTION IN FUNGI
• reproduce both asexually (genetically identical offspring) and sexually
• most fungi are haploid throughout their life cycle
• sexual reproduction occurs when hyphae of different mating types
(+ and -) meet and fuse together
BACK TO FUNGI HALL
FUNGAL EVOLUTION evolved at about the same time as
early plants – 460 million years ago
BACK TO FUNGI HALL
THE FUNGAL
PHYLA
Rhizopus stolonifer(black bread mold)
•600 species•coenocytic
CONTINUED
Rhizopus mycelium(moldy strawberries)
CONTINUED
Spinellus fusiger - mushroom parasiteCONTINUED
Pandora neoaphidis - parasitic fungus that killsgreen peach aphids
CONTINUED
Zygomycota Life Cycle
CONTINUED
mature zygosporeCONTINUED
Rhinocerebral Zygomycosis –causes lesions of the palate,face and brain
Conidiobolus coronatis - causes polyps in the noseor masses under the skin,found in tropical areasCONTINUED
•25,000 species•form a basidiocarp, a reproductive structure also known as a mushroom!
CONTINUED
DEADLY MUSHROOMS
Some Amanita species associated with oak treescontain alpha-amanitin which works by slowly attacking RNA polymerase, an enzyme in the liver. It ultimately affects the central nervous system and kidneys. Death often results if a liver transplant or other heroic measures are not performed. CONTINUED
Chlorophyllum molubdites -most common cause ofmushroom poisoningin the US
CONTINUED
Omphallotis olearius dine on rotting tree stumps, yum!!!
CONTINUEDBACK TO FUNGI CHARACTERISTICS
Sexual Reproduction in Basidiomycota
CONTINUED
basidium and basidiospores
CONTINUED
bracket fungus - hemlock varnish shelf fungus
CONTINUED
coral fungus
CONTINUED
•30,000 species•believed to have evolved most recently•live in salt, freshwater and terrestrial habitats•phyla includes morels, powdery mildews, yeasts and cup fungi
CONTINUED
sac fungi
CONTINUED
Sexual Reproduction in Ascomycota
•hyphae of 2 mating strains form gametangiafemale - ascogonium male -
antheridium
•gametangia fuse and move into ascogonium, nuclei pair but do not fuse•cells divide mitotically, each heterokaryotic hyphae grows and intertwines to form an ascocarp (reproductive body)•asci form on the surface of the ascocarp, near the tips of some hyphae•each ascus has 2 nuclei that fuse•each diploid nucleus undergoes meiosis to produce 4 haploid nuclei•haploid nuclei divide once by mitosis so that each ascus ends up with 8 haploid ascospores•ascus ruptures to release ascospores that germinate
CONTINUED – yes, there is a diagram!
CONTINUED
Sexual Reproduction in Ascomycota
asci with 8 sporesin each
CONTINUED
Xylaria polymorpha -aka Dead Man’s Fingers, often foundat the base of beech trees
CONTINUED
Xylaria polymorpha cut in half (note the asci - the small black dots!)
CONTINUED
•10,000 species•no sexual reproductive phase has been discovered•many are similar to ascomycetes
CONTINUED
Athlete’s foot - caused by Tricophytom ruburm• lives within and eats outer skin layers (parasite)
CONTINUED
Ringworm - can be causedby the same organism thatcauses Athlete’s Footor other organisms, eats skin (parasite)
CONTINUED
Penicillium roqueforti…DE-licious
CONTINUED
Aspergillus can be a parasite(eye infection causedby Aspergillus)
CONTINUED
some organisms inthis phyla can beused to make soy sauce(soy beanfermentation)
BACK TO FUNGI HALL
ECOLOGICAL IMPORTANCE and IMPACT
of FUNGI
•may have helped early plants obtain nutrients through a symbiotic relationship
•played an important role in plant evolution 460 million years ago
•many fungi are plant parasites responsible for 15-20% of crop loss yearly CONTINUED
•play an essential role in maintaining equilibrium in every ecosystem (even the human body) by recycling nutrients, breaking down wastes and keeping other populations in check
•replace essential nutrients that plants remove from the soil
BACK TO FUNGI HALL
wheat rust - produces sporesin barberry plants that then migrate to wheat fields
CONTINUED
corn smut…not for popping
CONTINUED
SYMBIOSIS•lichens and mycorrhizea
•fungus is usually an ascomycete (can be a basidiomycete)
•photosynthetic organism is green algae or cyanobacteria
CONTINUED
•what does each organism get from the relationship ?
•what is the ecological importance of these organisms ?
lichens
BACK TO ECOLOGY
fungi provide moist shelter for the algae, while the algae provide a constant food supply (through photosynthesis) to their fungal host
CONTINUED
lichens are often the first organisms to inhabit barren areas (succession), creating soil by breaking down rock and adding organic nutrients (from their decay)
lichen growing on gneiss
CONTINUED
•mycorhizzae are symbiotic relationships between the roots of most plants and fungi•the fungi fix nitrogen so that it can be used by plants, while they use the plants as a shelter and food source