Mushrooms, mould, and mildew Fungi in action Kingdom Fungi Mushrooms, mould, and mildew Fungi in action

Characteristics of Fungi In partners or as a group – what characteristics define a fungus (pl)? If you said: Eukaryotic Heterotrophic, but do not have an internal digestive system (have external digestion) Non vascular (no root system) Reproduce sexually and asexually You’d be right!

Wait...Fungi aren’t plants? Have a root system Autotrophs Cell wall composed of cellulose Fungi Non-vascular system Heterotophic Cell wall is composed of chitin

Structure of Fungi Some fungi are single-celled They are called yeasts Valuable economically – can you think why?

Structure of Fungi Most fungi are multi-cellular Body of a fungi generally occurs below ground Body = mycelium = a branching, mesh-like network of hyphae Where do you think most of the body of a fungus occurs? Above ground or below ground

Structure of Fungi cont. An individual filament is called a hypha (hyphae (pl)) One long continuous multicellular structure Hyphae have a structure unlike plant or animal cells; consist of long tubes of cytoplasm containing many nuclei; cytoplasm contained by a cell wall that consists of chitin; tubes separated into cell-like compartments by cell walls called speta (septum) -

Structure of Fungi cont. So what is a ‘mushroom’? It is the spore producing reproductive structure of a fungus, which is called the fruiting body Made of hyphae that are densely packed together Hyphae have a structure unlike plant or animal cells; consist of long tubes of cytoplasm containing many nuclei; cytoplasm contained by a cell wall that consists of chitin; tubes separated into cell-like compartments by cell walls called speta (septum) -

Fungal Nutrition Fungi release enzymes into their surrounding Enzymes break down the food externally Fungi then absorb the nutrients that have been released by the enzymes through its cell membrane One way of classifying fungi is through the four different ways that they obtain nutrients Hyphae have a structure unlike plant or animal cells; consist of long tubes of cytoplasm containing many nuclei; cytoplasm contained by a cell wall that consists of chitin; tubes separated into cell-like compartments by cell walls called speta (septum) -

Fungal Nutrition Parasitic Fungi absorbs nutrients from the living cells of a host organism Results in death of the host In this case, fungi generally lives inside the host organism

Fungal Nutrition Predatory Soil fungi whose mycelia have specialized structures for trapping prey Nematode caught in constricting rings of hyphae

Fungal Nutrition Mutualistic Fungi that have partnerships with other organisms (e.g. Plants, protists or animals) Both organisms involved in the partnership benefit from the relationship Another example = relationship many fungi have with plants. In this case, mycelia covers plant roots – increase surface area of roots , allowing plants to take in more nutrients and provide fungus with sugar (food) Eg. Lichen – an organism that results from a mutualistic relationship b/w a fungus and a photosynthetic plant or alga

Fungal Nutrition Saprobial Fungi that feed on dead or decaying organic matter i.e. They are decomposers Very important in nutrient recycling

Learning Check What is mycelium and where is it found? When you see a mushroom growing from a dead log, which part of the fungus are you observing?

Fungal Classification 5 Major Phlya Phylum Chytridiomycota (chytrids) Phlyum Zygomycota (zygomycetes) Phylum Deuteromycota Phylum Ascomycota (ascomycetes) Phylum Basidiomycota (basidiomycetes) Based on differences in reproduction and the structure of the fruiting body they produce

Fungi Imperfecti (Deuteromycota) Not known to reproduce sexually Generally types of moulds E.g. Penicillium mould; mould in blue cheese

Chytrids (P. Chytridomycota) Mostly unicellular Aquatic species (marine or freshwater) Spores have flagella (motile) Parasitic or saprophytes

Zygospore Fungi (P. Zygomycota) Multicellular and mostly terrestrial (soil) Include familiar bread and fruit moulds Generally reproduce asexually

Zygospore Fungi (P. Zygomycota) Reproduce sexually in unfavourable conditions to produce zygospores Diploid structure (2n) that develops after two haploid (n) hyphae of opposite types combine their nuclei. Thick wall develops around nuclei to protect it.

Sac Fungi(P. Ascomycota) Largest fungi group Develop small finger-like sacs called asci (contain spores) during sexual reproduction (similar to creation of zygospores) Saprophyte and parasites Includes yeasts, which reproduce by budding Sexual reproduction involves the fusion of two mating types to form spore-bearing asci

Club Fungi (P. Basidiomycota) Includes ‘mushrooms’, puffballs, and stinkhorns Most are decomposers, some form symbiotic (mutualistic) relationship with plants E.g. lichen Sexual reproduction involves the fusion of two mating types to form spore-bearing asci

Club Fungi (P. Basidiomycota) Fruiting bodies release spores called basidiospores from basidia (club-shaped hypha)

Reproduction Asexual Budding – a smaller cell develops while attached to a parent cell. Eventually, small cell is pinched off of parent cell to produce a new individual

Reproduction Asexual Fragmentation – a piece of mycelium breaks and forms a new individual Spore production Sexual reproduction - also involves spore production and often the creation of a fruiting body above ground Fig3.21 (hand-out)

The Importance of Fungi Fungi are: Decomposers – one of the most important groups for recycling materials along with Bacteris Form symbiotic relationships – esp. with plants. Without these relationships plant growth and productivity would be reduced Food source (e.g. Blue cheese, mushrooms) and used in food production (bread, beer)

The Importance of Fungi Fungi are: Sources of antibiotics (medicine) (e.g. Penicillin). The discovery of antibiotics revolutionized health care worldwide. Biocontrol – use fungi that target insects to control crop pests (e.g. Chinese caterpillar fungus; control of California potato beetles). This is cheaper and less damaging to the environment than using chemical pesticides

The Importance of Fungi Cause animal and plant disease (e.g. Every year 10 – 50% of world’s fruit harvest is destroyed by fungi!) (e.g. Athlete’s foot, ringworm) Food spoilage (mould)

Meet the worlds largest organism Honey mushrooms – give an inkling of what is below. http://www.scientificamerican.com/article.cfm?id=strange-but-true-largest-organism-is-fungus