Early Paleozoic Plants and Fungi Greened the Earth

More that 470 million years ago, during the early Paleozoic era, the first plants on Earth teamed up with soil fungi, in order to colonize the land.

This discovery was made by scientists at the University of Sheffield, along with experts from the Royal Botanic Gardens, Kew, Imperial College London and the University of Sydney, and it brought new insights on the evolution of the plants and fungi on dry land.

For the experiment, the researchers used a thalloid liverwort plant, because it's part of the most ancient group of land plants that still exist today, and it has kept many of the original features of its ancestors.

In a controlled-environment growth room that simulated a CO2-rich atmosphere, much like that during the Paleozoic era, they put together the plant and the fungi.

The result was that when the plant was colonized by the fungi, it rose its photosynthetic carbon uptake, growth and asexual reproduction.

And as the fungi provided essential soil nutrients, the plant grew and reproduced better, giving the fungi the carbon it needed to develop.

What the researchers noted was that every plant was supporting fungi 1-2 times the size of a tennis court.

This research was what science needed to confirm that in the early Paleozoic era, nearly half a billion years ago, ancient plant and soil-dwelling fungi worked together.

This theory has been suspected for a long time, without ever being proved, by lack of evidence.

“By studying these ancient plants we open a window on the past to investigate how the earliest land plants evolved,” said Professor David Beerling, from the Department of Animal and Plant Sciences at the University of Sheffield.

“Our results support the idea that the 'greening' of the Earth was promoted by a symbiosis between plants and fungi.

“It shows that plants didn't get a toe-hold on land without teaming up with fungi – this has long been suspected, but until now not investigated.

“It will require us to think again about the crucial role of cooperation between organisms that drove fundamental changes in the ecology of our planet.”

“Fungi are present in every type of habitat throughout the world and are essential for many plants to grow,” added Martin Bidartondo from the Jodrell Laboratory at the Royal Botanic Gardens, Kew.

“It is exciting that we are now beginning to discover the fungi associated with 'lower' plants, and that many more still remain to be investigated.”

These findings were published in Nature Communications.