4What are Fungi?Fungi are eukaryotic heterotrophs that have cell walls made of chitin (a carbohydrate).Fungi DO NOT ingest their food, but rather they digest food OUTSIDE their bodies and the ABSORB it! (Fungi are decomposers)Reasons Fungi Not Plants!No chlorophyllCell wall not CelluloseNO vascular tissueDo not photosynthesize(Not an autotroph)
5Structure and Function of Fungi Multicellular (except yeasts)Composed of hyphae—thin filaments one cell thickCross walls—cytoplasm and nuclei can move through openingsWithout cross walls—contain many nuclei
6Hyphae Structure Close-Up NucleiCell wallCytoplasmCross wallHyphae With Cross WallsHyphae Without Cross WallsSection 21-1
7Structure & Function of Fungi Except for yeasts, ALL fungi are multi-cellular and composed of tiny filaments called hyphae.The bodies of multicellular fungi are composed of many hyphae tangled together into a thick mass called a mycelium.The mycelium is well suited to absorb food.The fruiting body is a reproductive structure that develops from a mycelium that grows below the surface of the ground.
9A Mushroom Fairy RingMushrooms emerge in a fairy ring from an underground fungal mycelium, growing outward from a central point where a single spore germinated, perhaps centuries ago.
10Reproduction in FungiMost fungi reproduce both asexually and sexually.Asexual:In some fungi, spores are produced in structures called sporangia.Sporangia are found at the tips of specialized hyphae called sporangiophores.Sexual:Sexual reproduction involves a gametangium - a gamete-forming structure produced when the hyphae of opposing mating types of fungi meet.
11How Fungi Spread How Fungi Spread Fungal spores Scatter easily in the windMust land in favorableenvironmentTemperatureMoistureFoodSome are specialized tolure animals, fliesDisperse spores overlong distancesFIGURE 22-2 Some fungi can eject sporesA ripe earthstar mushroom, struck by a drop of water, releases a cloud of spores that will be dispersed by air currents.
1321-2 Classification of Fungi Fungi are classified according to their structure and method of reproductionThe 4 main groups of fungi are:Zygomycota (common molds)Ascomycota (sac fungi)Basidiomycota (club fungi)Deuteromycota (imperfect fungi)
14Zygomycota – The Common Molds Zygomycetes are the familiar molds that grown on meat, cheese, and bread.Ex: Rhizopus stolonifer (black bread mold).the rootlike hyphae that anchor the fungus to the bread are called rhizoidsthe stem-like hyphae that run along the surface of the bread are called stolons
15Figure 21-5 The Life Cycle of Rhizopus Section 21-2p. 531Zygospore (2N)Spores (N)Sporangium+ Mating type (N)StolonsRhizoids- Mating type (N)SporangiophoreGametangiaFERTILIZATIONMEIOSISSexual ReproductionAsexual ReproductionDiploidHaploid
17Ascomycota – The Sac Fungi The phylum Ascomycota is named for the ascus, a reproductive structure that contains spores.Ascomycetes are the largest phyum in the kingdom Fungi.Some are large and some are microscopic.Examples: cup fungi (large) and yeasts (microscopic).
18Figure 21-7 The Life Cycle of an Ascomycete Section 21-2p. 533Hypha (N)ConidiophoreConidia (N)+ Mating type (N)- Mating type (N)8 Ascospores (N)AscusZygote (2N)Ascus (N + N)Fruiting body (N + N)Hyphae (N + N)GametangiaAsciHyphae (N)DiploidHaploidFERTILIZATIONHYPHAE FUSEMEIOSISSexual ReproductionAsexual Reproduction
20Yeast is an Ascomycete Fungus YeastsUnicellular fungiAscomycetes—baking and brewingBudding—process of asexual reproduction—cell divisionAlcoholic fermentation to obtain energyByproducts—carbon dioxide and alcohol
21Yeast is an Ascomycete Fungus Yeasts are unusual, normally nonfilamentous ascomycetes that reproduce most commonly by budding. The yeast shown here is Candida, a common cause of vaginal infections.Candida sp.
22Some Ascomycetes Scarlet Cup Fungus Morel (a) The cup-shaped fruiting body of the scarlet cup fungus(b) The morel, an edible delicacy. (Consult an expert before sampling any wild fungus—some are deadly!)Scarlet Cup FungusMorel
24Sac Fungi - Ascomycota CUP FUNGI (visible to the eye) YEASTS (microscopic)
25Basidiomycota – The Club Fungi The phylum Basidiomycota gets its name from a specialized reproductive structure (called a basidium) that resembles a club.Includes:MushroomsShelf fungiPuffballsEarthstarsJelly fungiPlant rustsBird’s nest fungi
26Figure 21-8 The Life Cycle of a Basidiomycete Section 21-2p. 534Fruiting body (N + N)ButtonSecondary mycelium (N + N)Primary mycelium (N)+ Mating type (N)- Mating type (N)Basidiospores (N)Zygote (2N)Basidia (N + N)Gills lined with basidiaGillsStalkBaseCapFERTILIZATIONHYPHAE FUSEHaploidDiploidMEIOSIS
27Mushrooms – “Club Like” Fungi or Basidiomycete Fungi
29Some Basidiomycetes Shelf Fungi Giant Puffball The giant puffball Lycopedon giganteum may produce up to 5 trillion spores.Shelf fungi, the size of dessert plates, are conspicuous on trees.Giant Puffball
32The Club Fungi Diversity of Club Fungi Edible and Inedible Mushrooms Shelf fungiPuffballsEarthstarsJelly fungiRustsEdible and Inedible MushroomsAlmost identicalSome inedible can cause severe illness or death
33Diversity of Club Fungi PUFFBALLEARTH STARMUSHROOMSHELF FUNGIBIRD’S NEST FUNGIJELLY FUNGI
34Deuteromycota – The Imperfect Fungi Deuteromycota is an extremely varied phylum composed of those fungi that are not placed in other phyla.The term imperfect implies that these fungi do not appear to have sexual reproduction.Ex: Penicillium notatum – the source of antibiotic penicillin.
36Deuteromycota (Imperfect Fungi) -Regarded as imperfect because they exhibit no sexual stage has been observed in their life cycle-Members are not closely related and are not necessarily similar in structure or appearance; do not share a common ancestry, polyphyletic = coming from many ancestors – hmm weird
37TrufflesTruffles, rare ascomycetes (each about the size of a small apple), are a gastronomic delicacy.
38Truffles are round, warty, fungi that are irregular in shape Truffles are round, warty, fungi that are irregular in shape. They vary from the size of a walnut to that of a man's fist. Since the times of the Greeks and Romans these fungi have been used in Europe as delicacies, as aphrodisiacs, and as medicines. They are among the most expensive of the world's natural foods, often commanding as much as $250 to $450 per pound.Truffles are harvested in Europe with the aid of female pigs or truffle dogs, which are able to detect the strong smell of mature truffles underneath the surface of the ground. The female pig becomes excited when she sniffs a chemical that is similar to the male swine sex attractant. The use of dogs to find truffles is also and option.
3921-3 Ecology of Fungi All Fungi Are Heterotrophs Saprobes - Organisms that obtain food from decaying organic matterParasites - which harm other orgnismsSymbionts - live in close and mutually beneficial association with other speciesCapture live animalsPleurotus ostreatusLives on the sides of trees and trap worms to digest them
4021-3 Ecology of Fungi Fungi as Decomposers Maintain equilibrium in nearly every ecosystem by recycling nutrientsRelease digestive enzymes that break down organic material into simple molecules which diffuse into the fungus
4121-3 Ecology of Fungi Fungi as Parasites Corn smut Cause serious plant and animal diseases and a few cause diseases in humansPlant DiseasesSmuts, mildews, rustsCorn smutPlant mildewSpruce rust
4221-3 Ecology of FungiParasitic fungi cause serious plant and animal diseases:wheat rustmildew on fruit
43Corn SmutThis basidiomycete pathogen destroys millions of dollars’ worth of corn each year. Even a pest like corn smut has its admirers, though. In Mexico this fungus is known as huitlacoche and is considered to be a great delicacy.
44PenicilliumPenicillium growing on an orange. Reproductive structures, which coat the fruit’s surface, are visible, while hyphae beneath draw nourishment from inside. The antibiotic penicillin was first isolated from this fungus.
45Other Basidiomycetes Rusts and Smuts Rust infecting wheat leavesRust infecting a LeafWhitrot Smut digesting old wood
4621-3 Ecology of Fungi Human Diseases Athlete’s foot, ringworm Candida albicans (yeast)—oral thrushBacteria and yeast in the human body keep each other in check
4721-3 Ecology of Fungi Other Animal Diseases Cordyceps—grasshoppers in rain forests in Costa Rica
4821-3 Ecology of Fungi Symbiotic Relationships Mutualistic (both benefit)LichensFungus and an alga or a cyanobacterium or bothLive mostly on bare rock and in places that most other organisms cannot liveBreak down rock into soilAutotroph makes food, fungus absorbs water and nutrients and serves as an anchor
49Lichens: Symbiotic Partnerships Algal LayerMost lichens have a layered structure bounded on the top and bottom by an outer layer formed from fungal hyphae. Attachments formed from fungal hyphae emerge from the lower layer and anchor the lichen to a surface, such as a rock or a tree. An algal layer in which the alga and fungus grow in close association lies beneath the upper layer of hyphae.Fungal HyphaeAttachment Structure
51Lichens Covering a Rock A colorful encrusting lichen, growing on dry rock, illustrates the tough independence of this symbiotic combination of fungus and alga.
52Lichens are mutualistic symbiotic organisms Lichens are mutualistic symbiotic organisms. They have an ____________ fungus and a _________ or cyanobacterial portion. There are three lichen growth forms which are predominant in nature: __________________________________________________
54Symbiotic Relationships LichensA symbiotic associations between a fungus and a photosynthetic organism.Lichen can grow on dry, bare rock and are often the first organisms to inhabit an area (pioneer species).The lichen break down the bare rock, allowing other plants to grow.lichen
55Symbiotic Relationships MycorrhizaeA symbiotic associations of plant roots and fungi.Fungi increases the surface area of the plants roots.Its presence is often necessary for the growth of many plants.mycorrhizae
5621-3 Ecology of Fungi Mycorrhizae Plant roots and fungi Plant roots provide energy and fungus provides a large surface area for more absorption of water and minerals
57Mycorrhizae Enhance Plant Growth Hyphae of mycorrhizae entwining about the root of an aspen tree. Plants grow significantly better in a symbiotic association with these fungi, which help make nutrients and water available to the roots.Mycorrhizae
58Coenocytic = hyphae lack crosswalls PhylumEx’sCharacteristicsAsexualSexualZygomycotaBread MoldRhizopus a dung fungusChitin cell wallsCoenocytic = hyphae lack crosswallsUnflagel. spores drop from sporangiaGametangia fuse to create zygosporeAscomycotaYeast, morels, trufflesConidia on conidophoresHyphae + & - fuse to create ascospores in ascusBasidiomycotaMushrooms Puffballs, rusts, smutsCross walls in hyphaeAsexual by way of Conidophores which produce conidiosporesSexual when hyphae fuse in BASIDIA to producebasidiosporesFungi ImperfectiDeuteromycotaPenicillium,Athlete’s Foot fungus,Tomato BlightSimilarToBasidio andZygomyAsexual by conidia which produce conidophoresSexual reproNot known