Rainforest Fungi

Podcast

Rainforest Fungi

Transcript

How a fungus can fight cancer. I'm Bob Hirshon and this is Science Update.

Most of us avoid fungi – unless they're the mushrooms on our pizza. But plant scientist Gary Strobel, at Montana State University in Bozeman, goes to the ends of the earth looking for them. He's discovered that fungi that live in important medicinal plants often imitate their chemistry.

Strobel:
"That is, they're making the same medicinal compound as those plants make. If you can isolate these microorganisms and grow them in culture, you can potentially do the same with those organisms as has been done with penicillium, from which we get penicillin."

One cancer-fighting drug, called Taxol, is a candidate for this new approach. Taxol is now very expensive, and must be isolated from the tissue of yew trees. Doctor Strobel’s found that the fungi on yew trees also produce Taxol. He says the next step is to see if the fungus can be used to mass produce the drug.

Doctor Strobel says there are as many as a million other kinds of fungi in the world, most of them as yet unknown.

Strobel:
"We don’t know what’s there. And, if it disappears, likewise, all of its bugs, or microorganisms also disappear."

He's working to let people know that saving habitat preserves not only owls and elephants, but also potentially life saving creatures that you won't find on a wildlife calendar.

For the American Association for the Advancement of Science, I’m Bob Hirshon.

Making Sense of the Research

The diversity of life is important from an ecological perspective, increasing the stability of an ecosystem during times of change. And it is also important from an anthropocentric perspective, since many species have, or may in the future have, characteristics that benefit humans.

In the Science Update you just heard, a researcher discussed his work with various fungi. Many of these fungi live exclusively within host plant species. These fungi have evolved along with their hosts and, over millions of years, some of them have begun imitating their host plant’s biochemistry. Some plants depend on their fungi, as the fungi depend on them. When fungi occur within plants that have medicinal value, the fungi may become important to companies who wish to create lots of the substance in the laboratory. That’s because fungi may be cultured, or their genes may be transferable to other fungi that can be grown in labs. The finding may have great importance for the synthesis of the cancer drug Taxol, and other medicines.

Now try to answer the following questions:

1. What has plant scientist Gary Strobel discovered about fungi that live in important medicinal plants?
2. What is the importance of this discovery? How might it affect our lives?
3. What does Dr. Strobel hope to do with these microorganisms?
4. Where does Taxol come from? Why is it so expensive?
5. How many kinds of fungi are there in the world?
6. Why is it important to Dr. Strobel to save habitat?

Going Further

For a good follow-up to this Science Update, go to the Science NetLinks lesson Pond Life. This lesson explores the kinds of relationships that exist between organisms within an environment.

There is an interesting lesson found on the Access Excellence site called Medicine Man Viewing Guide. This lesson is designed to be used in conjunction with the movie Medicine Man. The questions in the guide help focus attention on the importance of preserving biodiversity, as well as how difficult it is to isolate active chemical compounds from naturally occurring substances.

For more information on microorganisms, visit Microbe Zoo.