Plants and Fungi

A friendly evolution

Published in

Age of Awareness

4 min readMar 9, 2020

There is a shocking amount of life under your feet when you wander through a forest. There are the roots of plants and trees and there are huge masses of many species of fungi. This underground fungi is mycelium, made up of a huge network of tiny filaments called hyphae. These filaments serve several useful purposes.

Some digest dead plant materials releasing minerals and improving soil quality. Some attack plants and kill them, providing openings in the forest. A third type of fungi insert themselves into the roots of plants and improve the plants. They are mycorrhizal fungi. Their friendship is symbiotic. Those are the fungi that are the topic of this story.

Mushroom ©Digital Juice — Used Under License

Many of these various kinds of fungi also produce mushrooms. Like apples are the fruit of an apple tree, mushrooms are the fruit of its mycelium.

The mycorrhizal fungi, trade carbohydrates from the plant for minerals and water. Plants produce carbohydrates through photosyntheses while fungi can’t. Fungi can get and transport minerals and water much better than plants. This trade helps the partners in a symbiotic fashion.

The Evolution of the Plant/Fungi Friendship

I was recently asked how these relationships could have evolved. I am not a botanist or mycologist, but I am a naturalist. I did some research and this is what I found.

The first plants and the first fungi

Land plants appeared on earth around 850 million years ago. They seem to have evolved from algae that grew in fresh water. Fungi arrived on land around 500 million years ago. Plants had a head start. Then, it took awhile before the two partnered up.

The first plant/fungi symbiosis

Scientists have examined 400 million year old plant fossils. They found fungal spores and hyphae inside of the cells of the plants. This is the first evidence of plant/fungi symbiosis. Similar fungi existed 460 million years ago, but there is no evidence they were symbiotic with plants. This bit of evidence suggests that symbiosis began sometime between 400 and 460 million years ago. The fossil record shows that fungi evolved along with plants to the present. We know that this relationship continues today.

The development of symbiosis

Laboratory tests have shown that these symbiotic relationships only develop under certain circumstances. For example,

the plant must have a multi-cellular structure
fungi must link to specific types of plant cells

Something changed over 400 million years ago that allowed symbiosis to occur. We don’t know the exact changes that started symbiosis. We do know that land plants needed to develop certain characteristics first. Fungi likely needed to develop some specific traits too.

Exploring genetics

The fossil record reveals changes in fungi and plants as they evolved over time. Gene studies can compare living fungi and plants to find differences. The differences between mycorrhizal and other fungi highlight the genetic requirements for symbiosis. Scientists are tracking genetic history. They want to find what changed, when it changed, and how the change affected symbiosis.

Why Should We Care?

Most people are unaware of the relationship between plants and fungi. Most people don’t care. People would care a great deal if these relationships didn’t exist.

Many plants have fungal associations. These fungi move nutrients from one plant to another and benefit whole ecosystems. They often help seedlings grow. Without them, plants couldn’t grow in many locations. Those that did grow would not be healthy.

Agriculture requires massive production of healthy plants to feed the world. Without the plant/fungi relationship, farmers could no longer feed the world. People care when they get hungry.
Trees also need these relationships. Without them, sustainable production of wood could only proceed at very low levels. People care when they lack shelter.
Plants, like cotton, provide us clothing. Without these relationships it would be hard to produce enough fiber for clothing. People care when they lack clothing.

The history of plant/fungi symbiosis helps us understand how nature currently operates. That knowledge helps us protect and enhance these critical relationships. That can benefit us all.

Conclusion

The topic is quite complex. It deals with:

the evolution of plants,
the evolution of fungi, and
the evolution of their friendship

Except for their spores, fungi tend to be soft and not preserved in fossils. This complicates understanding the history involved. Scientists know more about the evolution of plants. Yet some details remain elusive. The situation is open for further research. The discovery of more fossils can help further develop the history. Genetic studies can add more knowledge. As the science proceeds we will gain a better understanding.

The bottom line: Scientists don’t know a lot about the details. They have established some facts and developed some good ideas. They continue to research the topic.

Plants and Fungi

A friendly evolution

The Evolution of the Plant/Fungi Friendship

Why Should We Care?

Conclusion

Further Reading

Written by Jerry Haugen