Introductory Mycology BOT 461/561
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Transcript of Introductory Mycology BOT 461/561
Introductory Mycology BOT 461/561
What are fungi?
• Eukaryotic, spore-bearing, heterotrophic organisms that produce extracellular enzymes and absorb their nutrition.
Body Plan• unicellular (yeast), filamentous, or both (=dimorphic)
• Hypha (pl. hyphae) is the basic “cellular” unit in filamentous fungi; they may be septate or coenocytic (aseptate); collectively a mycelium
• limited tissue differentiation and division of labor
• somatic & reproductive structures
• plectenchyma: all organized fungal tissue, somatic & reproductive
Nuclear Status• Eukaryotic; uni, bi- or multinucleate• Haploid, diploid (less frequent)• Monokaryon (1 nucleus per hyphal compartment)
• Dikaryon (2 nuclei per hyphal compartment) • Homokaryotic
• Heterokaryotic
• Mitosis– intranuclear: nuclear membrane doesn't
breakdown during mitosis– centric in flagellated forms; typical centrioles
of eukaryotes– noncentric in nonflagellated forms; possess
spindle pole bodies (SPBs); differ from centrioles in lacking microtubular component
Organelles• typical eukaryote assemblage of organelles
+ fungal specific ones• mitochondria • endoplasmic reticulum • Golgi equivalents
single cisternal elements • vacuoles • microbodies
funx in fatty acid degradation, N metabolism
Cell Wall• well defined
• chitin
1-4 n-acetyal glucosamine -glucans
polymers of glucose
1-3 glucose
• cellulose in some
1-4 glucose
chitin -glucans
Chitin
Cellulose
1-3 glucan
•fungal specific organelles involved in cell wall growth
Spitzenkorper
associated with growing hyphal tips in septate fungi
chitosome
microvesicles transporting chitin synthases to growing cell wall
Nutrition• Heterotrophic• Secrete extracellular enzymes • Absorptive nutrition• Saprobes: decay dead organic matter• pathogens: biotroph, necrotroph • symbionts: parasites - commensals - mutualists
Spores - a minute propagative unit functioning as a seed, but differing from it in that a spore does not contain a preformed embryo
Fruiting body - any complex fungal structure that contains or bears spores; a sporocarp
Reproduction
• Sexual reproduction: spores meiotically derived nuclei
• Homothallic (selfing)
• Heterothallic (outcrossing)
• Monoecious or dioecious
• Genetic mating system
– MAT loci
– 1 to hundreds of “sexes”
• Asexual reproduction
– Spores with mitotically derived nuclei
Misc.
• Life cycle: simple to complex; wide variety
• Sporocarps: microscopic or macroscopic, limited tissue differientiation
• Habitat: ubiquitous
• Studied by mycologists!!!!!!
What are fungi?
• Eukaryotic, spore-bearing, heterotrophic organisms that produce extracelluar enzymes and absorb their nutrition.
Fungi vs. "fungi"
• Based on the phenotypic definitions or traits attributed to fungi, fungi do not comprise a single monophyletic group of organisms
• more than one evolutionary origin
• not all "fungi" are members of the Kingdom Fungi
FUNGI (e.g., mushrooms, yeasts)
M ICROSPORIDIA
METAZOA (Animals)
DICTYOSTELIDAE
MYXOGASTRIDAE
LOBOSA
ANGIOSPERMAE (Green Plants)
CHLOROPHYCEAE
RHODOPHYTA
GLAUCOPHYTA
OOMYCETES
PHAEOPHYCEAE (Brown algae)
CILIOPHORA
APICOMPLEXA
KINETOPLASTIDA
EUGLENOIDEA
ACRASIDAE
VAHLKAMPFIIDAE
PARABASALLA
DIPLOMONADIDA
Slime molds
Phylogeny Of Eukaryotes
(some water moldsSudden Oak Death)
based onDNAsequencedata
Some characters that separate the the Kingdom Fungi from “protistan fungi”
Kingdom Fungi Protistan fungi
mitochondria: cristae flattened cristae tubular
motile cells: no motile cells or motile cells with anteriorposterior flagellum or lateral
heterokont flagella cell wall carbohydrate: glucans, chitin glucans, cellulose lysine biosynthesis: alpha-aminoadepic acid (AAA) diaminopimelic (DAP)
storage compound glycogen mycolaminarins
sterols ergosterol fucosterol
Phyla: Chytridiomycota Oomycota(emphasized Zygomycota Myxomycotain class) Glomeromycota Dictyosteliomycota
Basidiomycota Ascomycota
General characteristics of the Phyla of the Kingdom Fungibasal lineages
Chytridiomycota: (800)•unicellular to mycelial (coenocytic) •zoospore with single posterior whiplash flagellum•aquatic & terrestrial•no sporocarp production
Zygomycota: (1000)•generally coenocytic mycelium •production of zygosporangia & zygospores•no sporocarp production
Glomeromycota: (200)•formerly part of Zygomycota•coenocytic mycelium•no known sexual reproduction•arbuscular mycorrhizae (Glomerales)•no sporocarp production
Basidiomycota: (22500)•septate mycelium•clamp connections•complex dolipore septa •dikaryotic, haploid mycelium •production of exospores (basidiospores) on a basidium •production of complex sporocarps
Ascomycota: (35000)•septate mycelium•simple septa •monokaryotic, haploid mycelium •production of endospores (ascospores)
in an ascus •production of complex sporocarps•often dominant asexual reproduction
Chytridiomycota
+Zygomycota
Ascomycota
Basidiomycota
Glomeromycota
Chytridiomycota
Phylogeny of Kingdom Fungi
Regularly septatehyphae
Multiple lossesof flagellum
X
X
chitin*glycogen*mito cristae*ergosterolpost smooth flagellum**share with animals asci + ascospores
basidia + basidiosporesdolipore + clamp connections
http://ocid.nacse.org/research/aftol/
Silurian 440 hypha, spores ?Ascomycota
Devonian 410 wood decay Basidiomycotamycorrhizae Glomeromycotazoosporangia Chytridiomycota
Carboniferous 360 zygospores Zygomycotaclamp connections Basidiomycota?fruit bodies
Permian 286 white rot Basidiomycota
Triassic 245 wood decay Basidiomycotamycorrhizae Glomeromycota
Jurassic 208 shelf fungus Basidiomycota
Cretaceous 144 rusts Basidiomycotapolyporesconidia Ascomycota
Tertiary 65 extant morphologies
Fossil Record of Kingdom Fungi - How old are fungi?
Hymenomycetesmushrooms, shelf fungijelly fungi, coral crusts, puffballs
Ustilaginomycetessmuts
Urediniomycetesrusts, marine yeastscrusts
3 Major Clades - Classes - of the Basidiomycota
Kingdom - Fungi Phylum - Basidiomycota
Class - HymenomycetesOrder - Agaricales
Family - AmanitaceaeGenus - Amanita
Species - A. muscaria
Amanita muscaria
Nomenclature
Introductory Mycology BOT 461/561 http://ocid.nacse.org/classroom/fungi/bot461/