Plantae Fungi Protista Monera Animalia Kingdom Fungi About 100,000 species Uses: • medicine • food Ecological value: • major decomposers • symbiotic relationships (N2 fixers) Problems: • some strains are deadly • athletes foot • destroy library books • destroy crops Some fungi are pathogens • About 30% of the 100,000 known species of fungi are parasites, mostly on or in plants. – American elms: Dutch Elm Disease Was once one of America's most dominant trees –American chestnut: chestnut blight Some fungi are pathogens • Other fungi, such as rusts and ergots, infect grain crops, causing tremendous economic losses each year. Some fungi are pathogens • Curse of the Mummy Some fungi are persistant Athletes Foot Fungi as Decomposers Kingdom Fungi Eukaryotic, absorptive Mostly multicellular (except few, e.g. yeast) Heterotrophic (decomposers & parasitic) Mycelium (body of hyphae) Kingdom Fungi • Firm cell walls (generally of “chitin”) • “Spores” as reproductive bodies • Unique chromosomes and nuclei • Includes molds, yeasts, rusts, and mushrooms • hyphae - the vegetative bodies of most fungi, constructed of tiny filaments • mycelium -an interwoven mat of hyphae Human hair Fungal hypha Septate hypha: • multicellular • walls divided by septa Ceonocytic hypha: • continuous cytoplasm mass • multinucleate • no septa Haustoria: • Modified hyphae found in parasitic fungi • Function: absorb nutrients from host • Some fungi even have hyphae adapted for preying on animals. Kingdom Fungi Division Chytridiomycota Division Ascomycota Division Glomeromycota Division Basidiomycota Division Zygomycota Division Deuteromycota Fig. 31-11 Hyphae Chytrids (1,000 species) Fungus -like protist Zygomycetes (1,000 species) Fungal hypha Glomeromycete s (160 species) Ascomycetes (65,000 species) ? Deuteromycota Basidiomycetes (30,000 species) 25 µm • The five fungal phyla can be distinguished by their reproductive features. Division Chytridiomycota • mainly aquatic. • Some are saprobes, while others parasitize protists, plants, and animals. • chitinous cell wall • flagellated zoospores • the most primitive fungi Division Zygomycota “Zygote fungi” (bread molds) Zygote = “mated” hyphal strands Live in soil, water Some are parasites 600 species Mated hyphal strands • The zygosporangia are resistant to freezing and drying. • When conditions improve, the zygosporangia release haploid spores that colonize new substrates. – Pilobolus aiming its spores. • The zygomycete Rhizopus can reproduce either asexually or sexually. PHYLUM GLOMEROMYCOTA • Previously With Zygomycota • Small Monophyletic Clade • Endomycorrhizae – Arbuscular Mycorrhizae • Produce branching Arbuscules Fig. 31-15 2.5 µm Plant-Fungal Relationships Mycorrhizae (“fungus roots”) 90% of tree species have this association Very important to absorption of water and nutrients Soil surface Plant roots Mycorrhizae Increases s.a. for absorption Division Ascomycota “Sac fungi” (truffles, yeast) Beer > 6,000 years Wine > 8,000 years Lichens Decomposers, pathogens “yeast” describes a form of fungi (i.e., non-hyphal) 60,000 species Division Ascomycota Scarlet cup truffles Morchella Division Ascomycota Roquefort cheese Close up of cheese showing blue-green mycelium of Penicillium roqueforti. Yeast LICHENS Crusrose Foliose Fruticose Lichen Lichen Anatomy • Ascomycetes are characterized by an extensive heterokaryotic stage during the formation of ascocarps. Division Basidiomycota “Club fungi” (mushrooms) Club-shaped reproductive structure Food Plant diseases 25,000 species Fairy Ring • The life cycle of a club fungus usually includes a long-lived dikaryotic mycelium. PHYLUM DEUTEROMYCOTA No Longer Exist!! • • • • • • 22,000 species. No known sexual stage. Saprophytic, parasitic and predatory. Many produce conidia. Most classified as Ascomycota. Fusarium wilt of tomato, potato and cotton. • Athletes foot, ring worm Division Deuteromycota “Imperfect fungi” (penicillin) Unrelated group Asexual No info on sexual cycle 25,000 species Penicillin Woops… now Ascomycota Candida albicans “yeast infection” Botrytis: “Noble Rot”