Mycology: the study of Fungi

Basidia “club-like”

Ascus “sac-like”

What do fungi “eat?” Decomposers break down complex molecules into sugars or consume sugars found in environment Examples: common bread mold (eats carbs in bread) shelf fungi on logs (eats carbs in cell wall of wood) white button mushrooms in store (eats sugars and cellulose in dung)

What do fungi “eat?” Symbiotic fungi receive their energy (carbohydrates) directly from a plant or algal partner Examples: mycorrhizal fungi (live on plant roots) lichens (contain algae)

What else do fungi “eat?” Predatory fungi, catch and digest other organisms (like nematodes) But still absorptive nutrition! Just have to catch it first…

Summary: What do fungi eat? Heterotrophs (cannot make their own food like plants) Extracellular, absorptive nutrition secrete enzymes outside of their bodies, “digest” the food outside of their cells and then absorb the molecules into their cells. Live in their substrate (food) How is this similar to us? What consequences/ advantages does it have?

Lichens

Fungi are made of hyphae (cells joined in thread-like strands)

Mushrooms are for sexual reproduction (~flowers) Mycelium = body of the fungus Hyphae = the “bricks” from which the mushroom is built

Why should you care about fungi? A few reasons: They make foods we like to eat Mycorrhizae are responsible for plant life on land and high productivity rates They decompose wood and organic matter Penicillin and other medicines They’re just really cool!

Mycorrhizae “myco” = fungus and “rhiza” = root Symbiotic association between plant roots and fungi Several different types of association (defined by structure of fungus:plant interface)

Fungi can access more of the soil because 1.Hyphae are smaller than plant roots Hyphae are 1/500th the diameter of a plant root hair Root Hair hyphae

Recap of mycorrhizal benefits Fungi increase the water and nutrients available to their plant partners leading to: Greater plant productivity (larger profits in the timber, fiber industries) Greater reproductive success for plants (higher yields for agriculture) Greater ecosystem stability Left: No mycorrhizal fungi Right: With mycorrhizal fungi

Fungi are important decomposers! Fungi are the only organisms that can completely decompose lignin (what makes wood hard) Lignin must be broken down before any other decomposition can occur (no fungi = no decomposition by anyone). Fungi also decompose cellulose to glucose and play a major role in the global carbon cycle.

Penicillium growth of the bacteria Staphylococcus aureus is inhibited in the area surrounding the invading penicillin-secreting Penicillium mold colony Dr. Andrew Fleming working at St. Mary’s Hospital in London noticed that mold growing on staph bacterial culture plates had killed the pathogen

Mushroom Poisoning Out of several thousand different kinds of wild mushrooms in North America, only five or six are deadly poisonous! Most cases of “mushroom poisoning” are a result of allergies, overindulgence, or food poisoning

Amanita Toxins extremely serious; 50% fatality symptoms are delayed by 6-24 hours liver and kidney damage violent vomiting, bloody diarrhea, and severe abdominal cramps no known antidote

Muscimol one of the oldest endotoxicants Symptoms appear 30 minutes - 2 hours Nausea and vomiting, confusion, mild euphoria, loss of muscular coordination, sweating, chills, hallucinations, or convulsions

Psilocybin hallucinogenic mushroom played an important role in religious rites of natives of Mexico and Central America symptoms similar to LSD heightened color perception, visual distortion, and hallucinations; profound anxiety

Bread Mold – a Zygomycete Fungi

Cup Fungi – Ascomycete Fungi Note the cup shapes and orange peel colour

Kingdom Fungi – you must know 5 Major Phyla 1.Phylum Zygomycota = the Bread Molds Rhizopus – black bread mold 2.Oomycota = the Water Molds Water mold, potato blight, mildew 3.Phylum Ascomycota = the Sac Fungi Yeast, morels, truffles 4.Phylum Basidiomycota = the Club Fungi Mushrooms, puffballs, bracket fungi, rusts, smuts, toadstools 5.Phylum Deuteromycota = the Fungi Imperfecti

-are primarily decomposers -asexual spores may be produced in sporangia -sexual reproduction occurs between + and – strains forming a 2n zygote; a zygospore develops and may lie dormant for a long period of time; meiosis occurs just before germination -only the zygote is diploid; all hyphae and asexual spores are haploid Zygomycota (Rhizopus) the Common Molds

Zygomycota – common molds The fungal mass of hyphae, known as the MYCELIUM penetrates the bread and produces the fruiting bodies on top of the stalks Mycelia = a mass of hyphae or filaments

Rhizoids = root-like hyphae The zhizoids meet underground and mating occurs between hyphae of different molds (SEXUAL REPRODUCTION)

Zygomycota (Rhizopus)

Basidiomycete or Club Fungi

Life Cycle of Basidiomycete Fungi

Bracket Fungi Puff Balls Mushrooms Jelly Fungi Basidiomycete Fungi that all produce Basiospores

Other Basidiomycetes Rusts and Smuts Rust infecting wheat leaves Rust infecting a Leaf Whitrot Smut digesting old wood

Deuteromycota – the Fungi Imperfecti Resemble Ascomycetes, but their reproductive cycle has never been observed Different from Ascomycetes because there is a definite lack of sexual reproduction, which is why they are called Imperfect Fungi Penicillium fungi Up Close

Crustose Foliose Fruticose

Mycorrhizae Mycorrhizae means “fungus-root”; mutualistic relationship between plant and fungi The plant photosynthesizes while the fungus more efficiently takes up nutrients and water from the rhizosphere than the roots would alone. Plant benefits include: Improved nutrient/water uptake Improved root growth Improved plant growth and yield Improved disease resistance Reduced transplant shock Reduced drought stress