Fungi 2/15/2019. Fungal Structure. Fungal Structure. Fungal Structure. Distinguishing characteristics of Fungi. Learning Objectives

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1 Learig Objectives Fugi By the ed of this uit, a studet should be able to List distiguishig characteristics, describe a typical life cycle, ad give examples of each of the followig fugal groups: chytridiomycetes, zygomycetes, glomeromycetes, ascomycetes, ad basidiomycetes Describe the body pla of a fugus Summarize the ecological sigificace of fugi as decomposers Describe the importat ecological role of mycorrhizae Characterize the uique ature of a liche Summarize some specific ways that fugi affect humas ecoomically Summarize the importace of fugal diseases to agriculture ad medicie; givig specific examples Distiguishig characteristics of Fugi Eukaryotic heterotrophs Secrete digestive ezymes exterally, absorb utriets Cell walls cotai chiti fibrous polysaccharide polymer of a N-acetylglucosamie (derivative of glucose) also foud i exoskeleto of arthropods Fugal Structure Threadlike filamets (hyphae) Brach ad form a tagled mass () Fugal Structure Threadlike filamets (hyphae) Brach ad form a tagled mass () Hyphae Perforated septa (cross walls) divide hyphae ito idividual cells Some are coeocytic form elogated, multiuclear cell Fugal Structure 1

2 Fugal Reproductio reproduce with Spores sexual asexual produced o aerial hyphae produced i a fruitig body Fugal Reproductio Giat Puffball (Calvatia gigatea) A sigle te-ich giat puffball has as may as 7 trillio (7,000,000,000,000) spores. If each of those spores grew ad yielded a te-ich puffball, the combied mass would be 800 times that of the earth. From the Corell Mushroom Blog, David Laders Yeast Yeasts are a type of sigle celled fugus highly reduced reproduce asexually by buddig Mitosis Meiosis Fertilizatio Life cycles Fugal Life cycles haploid Fugal Life Cycle mitosis Spores plasmogamy meiosis 2 + dikaryotic karyogamy Ex: Homo sapies diploid 2

3 haploid Fugal Life cycles Spores () Spores () mitosis asexual cycle of haploid dikaryotic plasmogamy meiosis diploid karyogamy Fugal Evolutio Chytrids (Chytridiomycetes) Produce flagellate cells o other fugi have flagella a shared characteristic of the opisthokots Probably earliest fugi to evolve from flagellate protist Chytridium covervae Chytrids (Chytridiomycetes) Chytrids (Chytridiomycetes) Chytrid ad Chytridiomycosis disease Massive amphibia die-off maily i tropics Caused by fugus Batrachochytrium dedrobatidis 3

4 Fugal Evolutio Hyphae are coeocytic septa form to separate the hyphae from reproductive structures Sexual reproductio hyphae of 2 differet matig types form gametagia Plasmogamy occurs as gametagia fuse Karyogamy produces zygote (2) zygote develops ito zygosporagium Sexual reproductio zygosporagium produces zygospores () zygospores germiate ad produce sporagia sporagia produce spores () which germiate ito ew hyphae Life Cycle Microsporidia Small, uicellular opportuistic pathoges that ifect eukaryotic cells May be the smallest ad simplest eukaryotes Example: Rhizopus stolioifer (black bread mold) 4

5 Microsporidia Previously classified with yeasts, bacteria, ad protista Geome studies suggest that microsporidia desceded from a zygomycete acestor Fugal Evolutio Glomeromycetes (Phylum Glomeromycota) Coeocytic hyphae reproduce asexually with large, multiucleate blastospores form mycorrhizae mutualistic symbiosis with plat roots Glomeromycetes (Phylum Glomeromycota) Mycorrhizae* form associatios with roots of trees ad herbaceous plats specifically, edomycorrhizal grow ito plat root cells called arbuscular mycorrhizae form tree-shaped structures * a descriptio of ecology, ot phylogey Cells of root cortex Root epidermis Mycorrhizal Associatios Vesicle Root hair Soil Roots supply orgaic utriets Fugus provides mieral utriets Type a quote here. Arbuscule Spore Johy Appleseed Cortex cell Hypha of fugus Pie w/o mycorrhizae Pie with mycorrhizae 5

6 Fugal Evolutio Ascomycetes (Phylum Ascomycota) iclude yeasts cup fugi morels truffles pik, brow, ad bluegree molds Have septate hyphae Ascomycetes Produce coeocytic sexual hyphae Followig plasmogamy, dikaryotic ( + ) hyphae form i a ascocarp* (fruitig body) Ascomycetes Karyogamy occurs at tips of hyphae (asci) followed by meiosis ad mitosis produces 8 haploid uclei that develop ito ascospores Ascocarp - fruitig body Asci - form sexual spores i groups of 8 *made of mookaryotic hyphae Ascomycetes (Phylum Ascomycota) Asexual reproductio ivolves formatio of colored spores (coidia) at the tips of specialized hyphae (coidiophores) Johy Appleseed Peicillium coidiophores 6

7 Fugal Evolutio Phylum Basidiomycota iclude the largest ad most familiar of the fugi mushrooms bracket fugi puffballs rusts smuts Septate hyphae a secodary forms after plasmogamy dikaryotic hyphae compact buttos grow ito mushrooms (fruitig bodies) called basidiocarps (Phylum Basidiomycota) Karyogamy takes place withi youg basidia o the gills of the mushroom each basidium produces 4 basidiospores Basidiospores released Secod meiotic divisio 1 HAPLOID () STAGE First meiotic divisio DIPLOID (2) STAGE DIKARYOTIC Type a quote STAGE here. ( + ) May basidiomycetes produce fairy rigs i laws Plasmogamy ad forests The circle wides as the fugi grow outward 6 Meiosis Zygote Johy Appleseed Karyogamy Gills Basidiocarp 5 Secodary 7