Basidomycota

1. Basidomycota Maggie Blackmon, Carolyn Poliseo, Jaime Swank

2. Hyphae • Septate hyphae • Septa divide hyphae into cells • Pores allow nuclei, ribosomes, and mitochondria to travel

3. Spore formation • Sexual or asexual • Formed from hyphae, basida, yeast, and other basidiospores • Cool video Spores Sterigma Basida Hyphae

4. Spore formation • Spores formed on basidia, released from sterigma • The hilar droplet releases the spore through "surface tension catapult.“ • Causes a sudden shift in the center of mass of the spore • Launches spores at 25,000g

6. Basidiomycota as Decomposers • Saprobe: a microbe that decomposes organic remains from dead organisms • Ex: Nidulariaceae(bird’s nest fungi), shelf fungi, and Marasmiusoreades

7. Basidiomycotaas Parasites • Pathogens • Pathogens: Any agent (in this case a fungus) that causes disease • Ex: Cryptococcus (seen in humans)

8. Basidiomycota as Parasites • Ex: • Rust fungi- produces reddish or brownish spots on leaves of plants • Phragmidiumviolaceumblackberry bushes produces pustules of violet teliospores • Melampsoridiumbetulinum(birch rust) forms certain spores on birch and larch leaves. • Smut fungi- affect plants’ reproductive systems • Ustilagonudaforms teliospores (7-8 µms) on wheat

9. Basidiomycota as Parasites • Symbionts • Symbiosis: an intimate association between individuals from two species • Ex: • Mycorrhizae- symbiotic association between a fungus and the roots of a vascular plant • Symbiosis between Lepiotaceae and leafcutter ants

10. Life Cycle of Basidiomycota: Monokaryotic Phase • Basidiospores (haploid sexual spores) are released from a mature fruiting body (basidiocarp, AKA mushroom) • A spore lands in fertile soil and germinates • This grows into a hypha, which grows into a mycelium • This is a primary mycelium, meaning each cell is monokaryotic (one nucleus) • It has only one type of nucleus (+ or -)

11. Dikaryotic Phase • If this mycelium meets up with another primary mycelium of the other nucleus type, they form a dikaryotic (two nuclei) cell • This is now called the secondary mycelium • The mycelium grows until the environment triggers it to grow into an aboveground mass • The basidiocarp forms a cap, underneath it are gills made of hyphae and basidia

12. Spore Formation • Basidia are dikaryotic, they contain a nucleus from each mating type • To prepare for meiosis, the nuclei fuse in a process called karyogamy • Next, the cell undergoes meiosis and four nuclei are formed, two of each mating type • Spores are produced and each gets a haploid nucleus • The spores break off and the cycle begins again • It is estimated that a mushroom with a cap 7.5 cm across makes 40 million spores an hour

13. Click me!

14. Roles of Basidiomycota: Decomposers • Decomposers of plant and waste materials – key in carbon cycle • Can attack houses and other wood structures causing economic damage

15. Food • Agaricusbisporus(common mushroom) • Help heart health and immune system • Lentinusedodes(Shiitake mushroom) • Antitumor, cholesterol-lowering, and virus-inhibiting effects • Pleurotusostreatus(oyster mushroom) • Antioxidant and anti-bacterial effects

16. Pathogens • Cryptococcus neoformans- human pathogen • Enters through lungs and can invade other organs, like the skin and brain • Opportunistic infection for AIDS patients • Also affects cats and dogs • Some Basidiomycetes are poisonous when eaten • Amanita phalloides (death cap) – caused the death of two Roman emperors and a pope

17. Other Uses • Amanita phalloidesproduces a toxin called phalloidin which is used in fluorescent stains by cell biologists to see cytoskeletons • Some enzymes produced by Basidiomycetes are used in paper production • Chemicals produced by some mushrooms are hallucinogens • Psilocybin mushrooms – “magic mushrooms”