FUNGIWow! Fungi plant growth - The

Private Life of Plants - David Attenborough - BBC wildlife -

YouTube

Fungi• non-motile

• heterotrophs

• defining characteristic of fungi is mode of getting food: “extracellular digestion and absorption”

• secrete digestive enzymes

into the environment, then absorb the nutrients released by those enzymes.

• most are decomposers: live on decaying organisms.

• some are parasites: extract food from living organisms

Kingdom Fungi

• fungi were once members of the plant kingdom

• some similarities include:

• cells are eukaryotic (true nucleus with many organelles).• most are stationary, anchored in the soil• reproduction can be asexual, sexual or both.

• However, fungi have evolved in a different direction than plants:

Plants FungiHave one nucleus per cell Often have many nuclei per cell

autotrophs (have chlorophyll) heterotrophs

Starch is the main storage molecule

Have few or no storage molecules

Most have roots No roots

Cellulose in cell walls Chitin in cell walls (like insects)

Most reproduce by seed None reproduce by seed

Fungi Structure & Function

made of hyphae: tiny threads of cytoplasm surrounded by plasma membrane & covered by cell wall

cell walls made of chitin (same as insect shells)

hyphae interwoven to creately mycelium: mesh of microscopic branching hyphae that are usually on or just below the surface of the ground.

the visible parts (stem and cap)of the fungi are the fruiting body (reproductive parts)

Fungal Feeding vast network of

mycelium underground form mycorrhizae

forms a symbiotic relationship with plant roots

gains sugars, starches, protiens and lipids from plant roots

provides plant with extension of root to get water and minerals

Fungi Reproduction reproduce asexually when a

piece of the hyphae breaks off or by releasing spores.

spores are haploid cells (have a single set of chromosomes)

spores are able to withstand unfavourable conditions and are carried by wind to germinate in other locations.

fungi can also reproduce sexually when opposite haploid hyphae grow towards each other and fuse to form a diploid zygospore (which has 2 sets of chromosomes).

Planet Wild - Fungi - YouTube

Negative Roles of Fungus:

• crop parasites (corn smut) – fungi cause a lot of damage to crops each year

• foot fungus – athletes foot caused by Trichyphyton sp

• chytrid – killing frogs

•Frogs: The Thin Green Line - Video: Full Episode - Amphibian Extinction - Chytrid Fungus | Nature | PBS

Positive Roles of Fungus:

• decomposers (or recyclers) of nutrients in ecosystems.

• vital component of many foods (blue cheese, mushrooms, baking and brewing (yeast).

• antibiotics (penicillin)

• Lichens act as air quality monitors by absorbing toxins in the soil and the air.

Yeast

Major Phyla of Fungi

Phylum Reproductive Structure

Examples

Zygomycota

(common molds)

Zygospores that contain sexual spores

Black bread mold

Pilobolus

Basidiomycota

(club fungi)

Club-shaped cell (basidium) contains sexual spores

Mushrooms, puffballs, shelf fungi

Ascomycota

(sac fungi)

Sacs called asci that contain sexual spores

Yeasts, truffles, morels

Chytrids Fungi with flagellated spores

chytrids

Zygomycetes

• Zygomycetes form a diploid spore (think “zygote”) that undergoes meiosis after germination. Zygomycetes also have asexual, haploid spores.

• Bread mold is a common zygomycete

• Another important zygomycete group is the mycchorrhyzae, fungi that infect the roots of most plants. These fungi have a symbiotic relationship with the plants: the fungi gather nutrients form the soil as an extension of the roots, and the plant supplies nutrients from photosynthesis.

Basidomycetes: Club Fungi

• Mushrooms are the most common club fungi. Others include rusts and smuts that harm crop plants.

• The visible mushroom is merely a fruiting body. The bulk of the organism is underground, a mat of hyphae (strands) called a mycellium that can be quite large. One example in Oregon covers 2200 acres (3 ½ square miles), to a depth of 3 feet, and it is at least 2400 years old.

Ascomycetes• Ascomycetes are sac fungi:

they produce spores in sacs.

• Truffles and morels are good examples of ascomycetes: they taste good!

• Penicillium, the mold that gave penicillin, the first antibiotic, is an ascomycete. Pennicillium also gives flavor to certain cheeses.

• Sac fungi also include some important single celled yeasts. Saccharomyces cerevesiae is used to make bread rise and also to ferment beer and wine. Candida albicans produces the common human yeast infections.

Zygomycota Basidiomycota Ascomycota

Chytrid