BIOL184 Fungi Notes

Bio 184 Fungi Notes
Fungi features

1. Heterotrophs
 Feed by absorption
 Don’t photosynthesize
 Don’t have mouth – don’t ingest
2. Multicellular filaments or single cells (yeast)
3. Hyphae – network of tiny filaments made of hyphal cells
 Divided into cells by septa
 Septa have pores – for cell to cell movement of organelles
 Coenocytic fungi – no septa, continuous cytoplasm with hundreds of nuclei
 Mycelium = mass of hyphae
 Produce spores at tips of hyphae
4. Chitin – cell wall
5. Have heterokaryotic stage in lifecycle
 Due to plasmogamy- cytoplasm fuses but nuclei don’t immediately
 Go diploid (2n) to heterokaryotic (n+n) to haploid (n)
6. Disperse via spores
7. Different number of spores produced, depending on phylum
8. Mycorrhizal association - symbiotic relationships with 90% of plants
 Mycorrhizae – fungus on roots ONLY
1. Ectomycorrizal fungi (Prepared Slide)
 Hyphae between plant cells
 Doesn’t enter cells
 Absorbs water and minerals
2. Arbuscular mycorrhizal fungi
 AKA endomycorrhizae (Prepared Slide)
 Penetrates the cell wall but not the membrane
 Increases surface area of cells because of branching of cells
 Helps plant absorb water and minerals
 Plants give them synthesized plant products like carbs

4 main fungal roles
1) Decomposers (saprotroph)
 Decompose organic material like cellulose and lignin
 Can be used to remove pesticides, oil spills
 Recycle carbon, nitrogen and other elements
2) Mutualists with plants
 Fungal endophytes in most plants
 = live entirely in tissue, often between cells
 *Different from mycorrhizal – not just on roots and totally within the plant tissue
 Only come out of plant in reproduction when plant is dead or dying
 Some endophytes produce toxins to defend the plant