Fungal Phyla 3 phyla but 4 groups: Phylum Zygomycota (zygomycetes or bread molds): Meiospores made by zygosporangium (resistant microscopic structure). Phylum Ascomycota (ascomycetes or sac fungi): Meiospores made in sac-like ascus. Asci (plural) containing in fruiting body called ascoma (plural ascomata). Phylum Basidiomycota (basidiomycetes or club fungi): Meiospores made on club-like basidium. Basidia (plural) contained in fruiting body called basidioma (plural basidiomata).
Fungal Phyla 3 phyla but 4 groups 4th group? Fungi that don’t make meiospores (to our knowledge) Called Imperfect Fungi Reproduce only asexually (by mitospores) Not a true phylum but a temporary holding group.
Fungal Phyla: Zygomycota Small group (1,000 species)
Fungal Phyla: Zygomycota Small group (1,000 species) Make coenocytic hyphae (no crosswalls).
Fungal Phyla: Zygomycota Zygosporangium is key trait: often thick-walled and stress-resistant No dikaryotic hyphae: karyogamy followed by meiosis. Zygosporangia of 3 genera of zygomycetes Zygosporangium photo
Fungal Phyla: Zygomycota Make two types of spores: –meiospores from zygosporangium –mitospores (asexual) from mitosporangia. These help fungus to spread rapidly. meiospores mitospores
Fungal Phyla: Ascomycota Largest group of fungi (32,000 species) Morel Scarlet cup Carbon fungus
Meiospores (called ascospores) made in ascus in ascoma (fruiting body) Dikaryotic hyphae and monokaryotic hyphae together form ascoma. Ascoma
Fungal Phyla: Ascomycota Mitospores often made by pinching off cells at tips of hyphae. These called conidia. Each can start new mycelium.
Fungal Phyla: Ascomycota Yeasts: an important group of (mostly) ascomycetes Fermentation by yeasts useful for making alcoholic beverages and in baking. Worth billions of dollars a year to industry. Modern industrial wine-making
Fungal Phyla: Ascomycota Yeasts: an important group of (mostly) ascomycetes Some yeasts can cause disease: yeast infections and others. Yeast infection between toes
Fungal Phyla: Ascomycota Some ascomata are edible and highly prized by gourmets Truffles (worth up to $320/pound) Morels Morel Truffle cut open Pile of truffles
Fungal Phyla: Basidiomycota Large group (22,000 species) Earth stars Inky caps
Fungal Phyla: Basidiomycota Meiospores made on club-shaped basidium in basidioma (fruiting structure) Dikaryotic hyphae predominate in life of organism, and basidioma made only of these hyphae.
Fungal Phyla: Basidiomycota Basidiomata commonly observed. A stinkhorn A shelf or bracket fungus A jelly fungus A mushroom
Fungal Phyla: Basidiomycota Sometimes form circle as fungus grows from initial point: “fairy ring”
Fungal Phyla: Basidiomycota Sexual reproduction: Usually do not make mitospores, but mycelium can become fragmented to form separate individuals.
Fungal Phyla: Basidiomycota Humongous fungus! Largest organism on planet? Armillaria in National Forest in Oregon reported to be 3.5 miles across, cover 2,200 acres. May be 2,400 yr old. Fig. 36.6 Aerial view of smaller forest patches infected by Armillaria in Montana
Fungal Phyla: Basidiomycota Importance: –decomposers Rotting log with basidiomata on it
Fungal Phyla: Basidiomycota Importance: –food (basidioma eaten, but beware of poisonous ones) Amanita (death cap fungus: A poisonous basidioma
Fungal Phyla: Basidiomycota Importance: –pathogens of plants (smuts and rusts cause billions of dollars in damage to grain crops). Corn smut Stem rust on wheat Ergot on wheat or rye Ergotism, LSD, Salem witch trials
Fungal Groups: Fungi Imperfecti Large group (17,000 species) Hyphae septate Reproduction asexual only, by conidia Most thought to be Ascomycota fungi, but until sexual reproduction observed we can’t be sure! Fig. 36.12, showing conidia of several genera
Fungal Groups: Fungi Imperfecti Importance –decomposers –food rotters (can make toxins: aflatoxins in peanuts) –food production (flavor cheeses: Roquefort, Bleu cheese) Bleu cheese
Fungal Groups: Fungi Imperfecti Importance –produce antibiotics (ex, penicillin from Penicillium) and other drugs (cyclosporin) Note inhibited growth of Staph bacterium near fungus colony
Fungal Groups: Fungi Imperfecti Importance –plant and animal diseases (human examples: athlete’s foot and ringworm) Ringworm on leg Athlete’s foot infections
Special Fungal Mutualisms Mutualism: relationship between 2 species where both benefit Lichens: partnership between fungi and unicellular photosynthesizer (green alga or cyanobacteria) Fig. 36.13
Special Fungal Mutualisms Fungus forms body and protects and directs photosynthesizer, obtains materials from partner Together, can colonize harsh environments. Fig. 36.14
Lichen Importance Primary producers in harsh environments (base of food chains) Ex, reindeer in arctic eat large amounts of lichens Some are pollution sensitive: used as bioindicators of air quality.
Special Fungal Mutualisms Mycorrhizae: Association of fungus with plant root Common: 90% of plants do this! Mutualism: fungus extends into soil and aids in uptake of nutrients (P, Zn, Cu in particular) for plant Fungus obtains sugars from plant.
Special Fungal Mutualisms Important in revegetation/reclamation of disturbed areas: if fungi not present, plants don’t do well!. Plant on left grown without mycorrhizal fungi
Special Fungal Mutualisms Two types: endomycorrhizae in which fungus penetrates root cells Ectomycorrhizae in which fungus penetrates between root cells. Fig. 36.15a Fig. 36.15b
Special Fungal Use: Biocontrol Biocontrol: Using an organism’s natural enemies against it Some fungi attack insect pests Some fungi capture and consume nematodes (roundworms) that can cause agricultural problems. Fly killed by fungus Nematode predator fungus showing ring-like traps holding worm
Plants: Kingdom Plantae Important: –Major producers in terrestrial ecosystems
Plants: Kingdom Plantae Important: –Vital for human food, medicines, clothing, building materials, etc. Foxglove: source of digitalin (heart med.) Corn Cotton Lumber from trees
Plants: Kingdom Plantae Important: –Create much of the oxygen in atmosphere (and ozone!) Aquatic plant making oxygen bubbles during photosynthesis
Oxygen and Ozone Ozone is pollutant at Earth’s surface At outer atmosphere, oxygen gas produces ozone layer Vital, as it absorbs lots of ultraviolet (UV) radiation UV radiation damages DNA in skin cells Can cause skin cancer.
The Ozone Hole Some pollutants damage ozone layer It’s getting thinner At South Pole, a hole has started to appear Getting larger.
The Ozone Hole Some pollutants damage ozone layer (getting thinner) At South Pole, a “hole” has started to appear.
The Ozone Hole UV light is one cause of skin cancer Australia already has highest skin cancer rate on Earth.
Plants: General Features Chemistry –chlorophylls a + b, carotenoids (accessory pigments that aid photosynthesis) –energy stored as starch
Plants: General Features Chemistry –cell walls of cellulose Fig. 5.9a
Plants: General Features Chemistry –review: starch and cellulose are both made of glucose. Fig. 3.27
Plants: General Features Water-saving features (most) –cuticle: waxy layer on body surface –stomata: specialized cells that form pores in surface (let CO2 in for photosynthesis, can close to prevent water loss when it’s dry) Glowing layer is cuticle
Plants: General Features Water transport tissues: vascular tissues –Xylem: dead cells that carry water. Walls rigid with lignin (reinforcing material, resists decomposition) –Phloem: living cells that carry sugars. Phloem tissue Xylem tissue
Plants: General Features Reproductive features –Sporic meiosis (form gametophyte and sporophyte bodies) –Gametes specialized (oogamy) eggs: contain genes and stores materials (large) sperm: contain genes. Small to be mobile –Gametangia specialized made of many cells (multicellular) with outside layer of protective cells (sterile jacket)
Plants: General Features Reproductive features –Gametangia specialized antheridium: gametangium that contains sperm archegonium: gametangium that contains an egg Archegonium Antheridium
Plants: General Features Reproductive features –Egg fertilized in archegonium –Zygote starts to grow in archegonium embryo: young sporophyte retained and nourished by parent sporophyte Young embryo in archegonium Older embryo
Plants: General Features Reproductive features –Make only meiospores (no mitospores for asexual reproduction) –These made in meiosporangia (spore containers), called just sporangia because no mitospores made –Inside meiosporangia, diploid cells called meiospore mother cells undergo meiosis to make meiospores (sometimes called just spores because no mitospores are made).
Plants: General Features General Life Cycle Fig. 37.3
Plants: Where from? Green algae: One line of green algae gave rise to all plants Fig. 32.12
Plants: Where from? Green algae. One line of green algae gave rise to all plants Plantae are monophyletic Fig. 37.2