Extension Communications
Extension 4-H Youth Building
Ames, Iowa 50011-3630
(515) 294-9915
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Extension Communications |
11/22/04
Contacts:
Christine Engelbrecht, Plant Pathology, (515) 294-0591, cengel@iastate.edu
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033,
jmcguire@iastate.edu
Garden column for the week of Nov. 26, 2004
Fungi to be Thankful For
Christine Engelbrecht,
Plant Pathology
Iowa State University Extension
This is the season when we give thanks for many blessings--family, friends, a bountiful harvest. We probably never think to be thankful for an unlikely blessing--fungi. When we think of fungi we usually picture dangerous toadstools, moldy basements, and nasty diseases of toenails and plants. In fact, many fungi provide useful services we could not live without. Perhaps we should be grateful for the many blessings of fungi.
The majority of fungi make their living as "saprobes," or consumers of dead organic matter, such as fallen leaves or downed logs. As the fungi decompose these dead plant bodies, they release the nutrients from the dead material back into the soil, where it can be used by living plants once again. These fungi are essential recyclers of nutrients. Besides simply removing dead organisms and preventing a pileup of dead plant material, these fungi allow other plants and animals to use the nutrients and grow. The natural world could not thrive without these important decomposer fungi.
Another way that fungi are indispensable to us is as helpers of plants, called mycorrhizae. "Mycorrhizae" means "fungus-root." The roots of nearly all land plants are intimately attached to thread-like fungal bodies. The fungus branches out from the roots in all directions and act as an extension of the plant's root system, absorbing extra water and minerals, which it gives to the plant. In return, the plant gives the fungus food in the form of sugars, so the relationship between the plant and fungus is mutually beneficial.
About 90 percent of plant species, including nearly all trees, are known to have mycorrhizae. Plants without mycorrhizae generally do quite poorly compared with those that have these fungal friends. Many of the mushrooms that have been popping up under trees during the fall are the aboveground fruiting bodies of mycorrhizal fungi, the only part of these fungi that we typically notice. Although they usually go unseen, fungi that serve as mycorrhizae are critical to the survival of the plants we rely on and enjoy.
The third group of fungi to be thankful for is perhaps the most obvious--the edible fungi! Hundreds of different species of fungi are edible, and some are among the finest delicacies in the world. Anyone who has ever tasted a morel fried in butter or eaten pizza topped with button mushrooms knows that our diets would be less flavorful without fungi. European truffles are so tasty that they can sell for over $450 per pound.
Although it is a simple, one-celled organism, yeast is a fungus that has been essential to our way of life for millenia. Yeast is critical for making bread and fermented beverages. Fermentation results when yeast cells consume the sugars in beverages or bread dough and give off alcohol and carbon dioxide. The alcohol is the primary product of interest for alcoholic beverages, while the carbon dioxide helps bread dough rise by filling it with air.
As we give thanks this holiday season, it may be time to acknowledge the contributions of an often-overlooked group of organisms--the humble fungi.
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Editors: Two color photos, suitable for publication, are available at right. Click on each thumbnail photo to go to the fullsized photo. The top picture's fullsize photo is 176K and the bottom picture's fullsize photo is 284K. Caption: Mycena leinana, a mushroom-producing decay fungus. (Photo from the American Phytopathological Society) |
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| Caption: Turkey Tail |  |