1. 1.The 2N megasporocyte nucleus undergoes meiosis to produce haploid nuclei One of these 1N nuclei divides multiple times by mitosis, producing several 1N clones. (The function of most of these cells is unknown.) Fig Double fertilization produces a 2N zygote and 3N endosperm

Kingdom Fungi

Characteristics of Fungi Fungi are NOT plants Absorptive heterotrophs Reproduce by spores *reproductive bodies are often the most visible “Ecologically active” *hyphae = tubular units of construction *secrete exoenzymes Justify this statement… Briefly describe an example in each of the following fungal lifestyles: decomposers parasites symbionts

Fig 31.1 mycelium fruiting bodies both are composed of hyphae

Fig 28.8 Proposed Phylogeny of Eukaryotes (Protista) Fig 32.2 ?

motile spores zygosporangia asci basidia Fig 31.4 Classification in these three phyla is based on sexual reproductive structures Where do chytrids live?

Hyphae tubular hard wall of chitin around the cell membrane septa (perforated cross- walls) may form compartments (± cells) multinucleate What do you think is the purpose of perforated cross-walls? *80% of plant diseases are caused by fungi Coenocytic hypha Septate hypha Haustoria*

Hyphal growth Hyphae grow from their tips Mycelium = extensive, feeding web of hyphae Mycelia are the ecologically active bodies of fungi This wall is rigidOnly the tip wall is plastic and stretches Where would you find the hyphae of most fungi? Why is SA important?

What does absorptive heterotrophic nutrition look like? Fungi get their energy and raw materials from organic sources in their environment The products of digestion diffuse back into hyphae Products diffuses back into hyphae for use Nucleus “hangs back” and directs metabolism

Modifications of hyphae Fig 30.2 (don’t worry about the terms we don’t discuss in class)

Reproduction by spores Spores are reproductive cells *Sexual *Asexual Produced *fruiting bodies *inside sporangia *directly on hyphae Amanita fruiting body (Basidomycota) Pilobolus sporangia (Zygomycota) Penicillium hyphae (Ascomycota) Classification of fungi is based on which mode of spore production? What is the primary purpose of spores?

Fungal Ecology Saprobes *Decomposers *Mostly of plants, some animals Parasites *Harm host *Mostly on plants, some animals Mutualists *Lichens *Mycorrhizas

Zygomycota – “zygote fungi” Sexual - zygosporangia Asexual spores - common Hyphae have no cross walls Grow rapidly Fig 31.6 Rhizopus on strawberries

Fig 31.7 Life cycle of Rhizopus You are not responsible for the details of this life cycle. Life cycle is predominantly haploid Asexual sporangium with spores inside Sexual zygsporangium with one zygospore Fig. 31.7

Ascomycota – “sac fungi” Sex. – asci Asex. – common Cup fungi, morels, truffles Important plant parasites & saprobes Yeast - Saccharomyces Most lichens A cluster of asci with spores inside

Ascomycota – “sac fungi”

Aleuria 1 cm

Fig 31.9b Tuber melanosporum The black french truffle

Basidiomycota – “club fungi” Sex – basidia Asex – not so common Long-lived mycelia Rusts & smuts – primitive plant parasites Mushrooms, puffballs Enzymes decompose wood Mycorrhizas SEM of basidia and spores See Fig

From: Marasmius oreades - “Fairy Ring”

A rust growing on a currant leaf 0.5 cm

Inocybe, contains muscarine Boletus edulis Cantharellus, the chanterelle Amanita, “death angel”

Fomitopsis

Mushroom Life Cycle Fig Nuclear fusion in basidium Meiosis Hyphal fusion of haploid mycelia haploid mycelium young basidia - the only diploid cells mycelium and fruiting body are dikaryotic N 2N N+N

“Alternative” fungal lifestyles Yeasts Molds Mycorrhizas Lichens

Yeasts Single celled fungi Adapted to liquids *Plant saps *Water films *Moist animal tissues Candida Saccharomyces

Molds Rapidly growth Asexual spores Many of human importance *Food spoilage *Food products *Antibiotics, etc. Fig Antibiotic activity Noble Rot - Botrytis

Mycorrhizas “Fungus roots” Mutualism between: *Fungus (nutrient & water uptake for plant) *Plant (carbohydrate for fungus) Several kinds *Zygomycota – hyphae invade root cells *Ascomycota & Basidiomycota – hyphae invade root but don’t penetrate cells Extremely important ecological role of fungi!

Lichens “Mutualism” between *Fungus – structure *Alga or cyanobacterium – provides food Form a thallus *Foliose *Fruticose *Crustose Fig By what process do these symbionts produce food for the fungus?

Lichen internal structure Lobaria Fig What do the fungi provide in this symbiotic relationship?

Lichens as biomonitors Thalli act like sponges *Airborne dust, minerals, etc. adsorb to the lichen surface Some species more sensitive Which species are present can indicate air quality Most resistant species can also be analyzed for pollutants

Lichen diversity These photos taken by Fred Rhoades Visit: Fred Rhoade's Lichen PageFred Rhoade's Lichen Page

Caloplaca & Verrucaria

Two species in the fruticose lichen of the genus, Cladonia

Peltigera

Basidiomycote lichen, Omphalina 1 cm