1

Fungi

2

How Fungi Affect Other Organisms

Fungi may be harmful (parasites), or helpful, or even necessary to other organisms.

3

How Fungi Affect Other Organisms

Fungi and Disease• Cause many serious diseases – both in

plants and animalsIn plants – • Mildew• Dutch Elm Disease• Chestnut Blight• Corn smut and other

crop diseases

https://www.flickr.com/photos/judybaxter/1227037/

4

How Fungi Affect Other Organisms

Fungi and Disease• Fungi that grow on

foods can produce chemicals that are toxic (poisonous) when eaten– Ergot of Rye causes ergot

poisoning that can be fatal Claviceps purpurea, the fungus that causes ergot poisoning; fruiting body growing on barleyPublic Domain http://en.wikipedia.org/wiki/File:Claviceps_purpurea.JPG

5

How Fungi Affect Other Organisms

Fungi and Disease• Fungi that grow on

foods can produce chemicals that are toxic (poisonous) when eaten– Aflatoxin – cancer causing in

small doses, fatal in large doses, produced by a fungus that grows in stored corn or peanuts

Aspergillus, the fungus that produced aflatoxin, growing on peanuts

Photo by International Institute of Tropical Agriculture

Attribution-NonCommercial License https://www.flickr.com/photos/iita-media-library/4751580303/

FYI: Aflatoxin comes from Aspergillus + flavus + toxin

6

How Fungi Affect Other Organisms

Fungi and Disease• Fungi also cause

– Athlete’s Foot– Ringworm– Lung disease in poultry

• Some fungi can be used to help control insect pests, for example Gypsy Moth caterpillars.

RingwormPhoto by Grook Da Oger http://commons.wikimedia.org/wiki/File:Herpes_circin%C3%A9_01.jpg

7

How Fungi Affect Other Organisms

Fungus-Root Associations• Occur in ~80% of plants• A mutualistic association• 2 types caused by different

kinds of fungi

8

How Fungi Affect Other Organisms

Fungus-Root Associations1. Endomycorrhizae (also

called vesicular-arbuscular mycorrhizae) – part of the fungus grows within

the cells of the roots – found on most flowering

plants, including grasses (Angiosperms)

9

How Fungi Affect Other Organisms

Fungus-Root Associations

1. Endomycorrhizae

Public Domain: http://en.wikipedia.org/wiki/File:Arbuscular_mycorrhiza_microscope.jpg

10

How Fungi Affect Other Organisms

Fungus-Root Associations2. Ectomycorrhizae

–grows around the root and in-between the outer cells of the root

– does not enter the cell–gives roots a thickened appearance– primarily on woody trees and

shrubs including all pines, willow, oak and beech trees

11

How Fungi Affect Other Organisms

Fungus-Root Associations

2. Ectomycorrhizae

Ectomycorrhizae on pine rootsPhoto by Randy Molina, Public Domain, a work of the Forest

Service of the United States Department of Agriculture

http://commons.wikimedia.org/wiki/File:Ectomycorrhizae_001.jpg

12

How Fungi Affect Other Organisms

Fungus-Root Associations

Benefits to plants:

1. Increase the solubility of minerals in the soil – particularly phosphorus

2. Improves the uptake of nutrients (N, P, K) for the host

3. Protects against plant pathogens

13

How Fungi Affect Other Organisms

Fungus-Root Associations

Benefits to plants:

4. Produces plant growth hormones

5. Moves carbohydrates from one plant to another (vital for non-green plants such as Indian Pipe)

14

How Fungi Affect Other Organisms

Fungus-Root Associations

Benefits to Fungi–A source of carbohydrate

(food)

15

How Fungi Affect Other Organisms

Lichens:• A mutualistic relationship

between a fungus and an alga

• The alga is autotrophic and produces food.

16

How Fungi Affect Other Organisms

Lichens:• The fungus provides water

and minerals for the alga.• Together they can live in

many places neither could survive alone, and where few or no other organisms can live either.

17

How Fungi Affect Other Organisms

Lichens:• Release acids that breakdown rock

so are often the first organisms to grow in barren rocky areas

• Are the primary source of food for reindeer and caribou in wintertime

• Are important indicators of air pollution (They do not grow well if air is polluted.)

18

Lichens

British SoldiersPhoto by Louise K. Broman, Public Domain:

http://en.wikipedia.org/wiki/File:Cladonia_cristatella_EPA.jpg

Reindeer LichenPhoto by Jason Hollinger

http://commons.wikimedia.org/wiki/File:Shrubby_Reindeer_Lichen_(2451758190).jpg

Wolf LichenPhoto by Jason Hollinger

http://en.wikipedia.org/wiki/File:Letharia_vulpina_JHollinger_crop.jpg

Public Domain: http://en.wikipedia.org/wiki/File:Lichen_reproduction1.jpg

Photo by Roantrum http://en.wikipedia.org/wiki/File:N2_Lichen.jpg