1407 CHAPTER 31 FUNGI 2011

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1407 CHAPTER 31 FUNGI 2011 Powered By Docstoc
					  BIOLOGY 1407
  CHAPTER 31

KINGDOM FUNGI AND
     LICHENS
        KINGDOM FUNGI
•Multicellular
•Mostly terrestrial
•Absorptive heterotrophic nutrition.
•Parasitic, saprophytic or mutualistic.
•Chitin cell walls.
•Do not produce flagellated cells.
•Septate (divided by cross walls)and
 non septate (no cross walls) hyphae.
•Vegetative thallus haploid, mycelium
Fungi as Decomposers
Fungal Mycelium
Hyphae
Predatory Fungi
          Hyphae




                   Non-Septate

Septate
Fungal Life Cycle
Fig. 31-8




               Animals (and their close
               protistan relatives)




                                          Opisthokonts
UNICELLULAR,
FLAGELLATED    Nucleariids
ANCESTOR

               Chytrids


               Other fungi
           Fungal Phylogeny
• DNA evidence suggests that fungi are
  most closely related to unicellular
  nucleariids while animals are most
  closely related to unicellular
  choanoflagellates
• This suggests that fungi and animals
  evolved from a common flagellated
  unicellular ancestor and multicellularity
  arose separately in the two groups
• The oldest undisputed fossils of fungi are
  only about 460 million years old
Fig. 31-9




     Fossil
    460 Million
    Years Old




                  50 µm
          Microsporidia
• Unicellular
• Parasites of Animals and Protists
• They have tiny organelles derived
  from mitochondria but not
  conventional mitochondria
• Molecular comparisons indicate they
  may be closely related to fungi
• Parasitic Lifestyle
Fig. 31-10




             Host cell
             nucleus

             Developing
             microsporidian


             Spore
Fig. 31-11                                    Hyphae          25 µm
             Chytrids (1,000 species)




             Zygomycota (1,000 species)




                                               Fungal hypha
             Glomeromycota (160 species)




             Ascomycota (65,000 species)




             Basidiomycota (30,000 species)
Fig. 31-UN6
Phylum Chytridiomycota
 •Flagellated Zoospores and Gametes
 •Absorptive Nutrition
 •Chitin Cell Walls
 •Most Produce Hyphae
 •Metabolism Similar to True Fungi
 •Primitive Fungi
 •Retain Flagella
Phylum Chytridiomycota
     PHYLUM ZYGOMYCOTA
•Coenocytic thallus with nonseptate hyphae.
•Form endomycorrhizal associations
 with thousands of vascular plants.
•Asexual reproduction - upright
 sporangiophore with a sac-like
 sporangium at the tip.
•Sexual reproduction by conjugation
 and zygospore formation, no fleshy
 fruiting bodies.
•Black bread mold - Rhizopus stolonifera
Rhizopus stolonifera Life Cycle
Rhizopus
Rhizopus – Sexual
  reproduction
 PHYLUM GLOMEROMYCOTA

• Previously With Zygomycota
• Small Monophyletic Clade
• Endomycorrhizae – Arbuscular
  Mycorrhizae
• Produce branching Arbuscules
Fig. 31-15




             2.5 µm
 PHYLUM ASCOMYCOTA

•30,000 species.
•Sac or cup fungi.
•Perforated cross walls or septa.
•Produce dikaryotic hyphae during
  the life cycle.
•Sexual reproduction involves
 the formation of an ascocarp with
 elongate cells (asci, ascus singular)
 that produce ascospores.
   PHYLUM ASCOMYCOTA
•Three types of ascocarps are produced.
   •Apothecium - Cup like shape.
   •Perithecium - Flask like shape.
   •Cleistothecium - Globose, no opening.
•Asci make up the inner lining of the
 ascocarps.
•Asexual reproduction by the production
 of conidiospores (spores that bud
 from the tip of the hypha).
•Conidiophore
•Many parasitic ie. Chestnut blight,
 Truffles, yeast
PHYLUM ASCOMYCOTA
PHYLUM ASCOMYCOTA


           Ascocarps
Ascomycota Types
Aspergillus
Ascomycota - Structure
PHYLUM BASIDIOMYCOTA
•25,000 species.
•Some have very complex life cycles.
•Basidium - Club shaped terminal cell
 that produces sexual spores.
•Basidiospores - Sexual spores.
•Asexual spores are not conidia.
•Many have dolipore septa.
•Produce dikaryotic cells.
•Mushrooms, bracket and shelf fungi,
 smuts and rust, polyporous fungi.
Basidiomycota Types
Fig. 31-18
             Maiden veil fungus
             (Dictyphora), a
             fungus with an
             odor like rotting
             meat




                                  Puffballs emitting
                                  spores


                                  Shelf fungi, important
                                  decomposers of wood
PHYLUM BASIDIOMYCOTA
PHYLUM BASIDIOMYCOTA

              Basidiospores




   Basidium
Mushrooms
Basidiospores
PHYLUM DEUTEROMYCOTA
    No Longer Exist!!
•22,000 species.
•No known sexual stage.
•Saprophytic, parasitic and
 predatory.
•Many produce conidia.
•Most classified as Ascomycota.
•Fusarium wilt of tomato, potato
 and cotton.
•Athletes foot, ring worm
FUNGI IN THE ENVIRONMENT



     •Decomposers
     •Plant Diseases
     •Lichens
     •Endophytes
     •Mycorrhizae
        •Endo and Ecto
Fig. 31-25




 (a) Corn smut on corn   (b) Tar spot fungus on   (c) Ergots on rye
                             maple leaves
Fig. 31-25a




              (a) Corn smut on corn
Fig. 31-25b




              (b) Tar spot fungus on
                  maple leaves
Fig. 31-25c




              (c) Ergots on rye
Fig. 31-22
Fig. 31-24




             Ascocarp of fungus
                                                 Soredia
                                  Fungal
                                  hyphae Algal
                                         layer




             Algal cell
             Fungal hyphae
          LICHENS

                    Crusrose



Foliose             Fruticose
Fig. 31-23




                                      Crustose
                                     (encrusting)
    A fruticose (shrublike) lichen   lichens




                                      A foliose
                                     (leaflike)
                                     lichen
The Two Main Types of Mycorrhizae
• In ectomycorrhizae, the mycelium of the fungus
  forms a dense sheath over the surface of the root
• These hyphae form a network in the apoplast, but
  do not penetrate the root cells
Mycorrhizae
Fig. 37-12a-1




                       Epidermis   Cortex   Mantle           100 µm
                                            (fungal
                                            sheath)



                                            Endodermis


                                            Fungal
                                            hyphae
                                            between
     Mantle                                 cortical
     (fungal sheath)                        cells        (colorized SEM)
 (a) Ectomycorrhizae
• In arbuscular mycorrhizae, microscopic fungal
  hyphae extend into the root
• These mycorrhizae penetrate the cell wall but not
  the plasma membrane to form branched arbuscules
  within root cells
Fig. 37-12b-1




                     Epidermis           Cortex                              10 µm
                                                  Cortical cells


                                                  Endodermis

     Fungal                                       Fungal
     hyphae                                       vesicle
                                                  Casparian
                                                  strip
     Root
                                                  Arbuscules
     hair
                                                  Plasma
                                                  membrane     (LM, stained specimen)
 (b) Arbuscular mycorrhizae (endomycorrhizae)
FUNGI HUMAN IMPACT

 Fermentation
 Antibiotics
 Food Processing
 Food
 Plant Disease
 Animal Disease
 Agricultural Diseases

				
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