Moss frozen 400 years ago lives today

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Moss that was frozen under the Teardrop glacier on Ellesmere Island in Canada 400 years ago,  University of Alberta biologist Catherine La Farge noticed one day in as she walked along the edge of the ice, appeared to have a greenish tinge to it. She brought it back to a research laboratory found that the moss though having been frozen for hundreds of years, was still very much alive.

Catherine La Farge has watched the ice retreat up to four meters a year. Camping out at the toe of Teardrop glacier during the Arctic summers is all in a day’s work to her.

Living there during the summer months has given La Farge the chance to see what no one else has ever seen, what has been entombed under the ice for centuries. She has gotten to see, among other things, old rocks, mud, and — most importantly to her — ancient moss,  which is her special area of study.

Besides the Ice Age, there was a period called the Little Ice Age (1550-1850). La Farge’s frozen moss had been hidden under the ice since then. An experiment she conducted found that the moss was able to regenerate itself, and revive, despite having been frozen for so long.

La Farge’s experiment involving the moss specimen she collected in 2009 was published just this week in the Proceedings of the National Academy of Science. Her findings are shaking up basic assumptions that about land plants and their ability to regenerate themselves despite having been placed in adverse conditions for long periods of time.

When scientists used to come across  plant material that had been frozen under an Arctic glacier, they assumed the plant was dead. As these specimens looked like they were discolored and lifeless, there was little reason for them to think otherwise.

Mosses behave differently, though from most other land plants. They are not like the land plants that we know best. They do not have vascular tissue that helps pump fluids around different parts of the organism. Being completely desiccated during long Arctic winters doesn’t kill them, as it would most other plants.

Upon inspecting the samples that she’d brought back to the lab, La Farge  noticed a tiny green stem. Two possible explanations occurred to her.

“Either it kept its color under the glacier or it grew after the moss emerged 400 years later.”

She decided to conduct an experiment to discover which of the explanations was correct.

After she ground up the old plant material, La Farge then put it in petri dishes full of potting soil. She set it in the grow chamber next to her office. All that was left to do was to monitor the dishes and watch for signs of life. That’s exactly what she, graduate student Krista Williams, and master’s student David Wilkie did next.

Before long, in about four to six weeks, tiny green filaments or strands called protonema began to grow.

A few months later, a dish was almost full of green moss from cells frozen for 400 years. Seven of the twenty-four samples potted produced new growth.

“It was just incredible,” said La Farge. Her research work has given scientists another way to think about the basic life systems of plants.

“Now we have Little Ice Age moss material that produced juvenile plants.”

What are the implications of La Farge’s experiment with the moss? According to her, “Now we have to think there may be populations of land plants that survived that freezing. It makes you wonder what’s under the big ice caps in the Arctic and Antarctic and alpine glaciers.

“And we have a 400-year-old lineage of genetic material,” she added.

Other types of plants might not be as successful at surviving under ice as mosses. Mosses have been around for 400 million years old and are very hardy and ancient, she stated. They played a key role in moving life from water to land in evolution, evolved from green algae, and were the forerunners of other land plants.

Mosses, unlike most other plants, reproduce by cloning their cells so “all you need is even one cell to survive.”

Also, moss cells can reprogram themselves to start growth all over again. The scientific term for this is that mosses are totipotent.

La Farge’s work shows that the totipotency of a cell, its ability to regenerate,  doesn’t diminish with age, at least not over 400 frozen years. She believes that even older specimens of moss found under sheets of ice could, potentially, be revived back to life.

“If we could find some moss that went back 1,000 years or 5,000 years we may find some material that could be revived. But it all depends on the specific way the material is buried and the conditions.”

The kind of moss  La Farge collected are known as bryophytes.

Medical researchers in Germany are already using bryophyte cells — basically moss stem cells — in medical research. The resilience of the cells, as shown by La Farge’s research, could be a factor in their use.

Another use for this sort of moss might be to send specimens of it to Mars before we attempt to send humans there to colonize the planet. According to La Farge, it might be worth seeing how well moss survives the cold dry climate, she said.

“We’re not really dealing with a moonscape on the Arctic, but we’re definitely under pretty extreme conditions,” she stated. “We now talk about people . . . wanting to go to Mars and starting a whole new world out there. If you were going to send any kind of plant up there to see whether it could survive, bryophytes would probably be one of your key systems to try.”

Another implication of La Farge’s research has to do with the shrinking biodiversity that’s happening around the planet. Perhaps the frozen world under glaciers could provide an “unrecognized genetic reservoir.”

 

Written by: Douglas Cobb

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