Plants re-grow after five centuries under the ice
While monitoring the retreat of the Teardrop Glacier in the Canadian Arctic, scientists have found that recently unfrozen plants, some of which had been under ice since the reign of Henry VIII, were capable of new growth.
While in the field, the researchers from the University of Alberta discovered that the receding ice--which has doubled from 2 meters per year in the 1990s to 4.1 meters per year in 2009--had uncovered lots of mosses and other non-vascular plants, including more than 60 plant species. Upon careful examination, the scientists were impressed by how well preserved the delicate bodies were; the stems and leaf structures were perfectly intact, although some of them were only one-cell layer think. Using radiocarbon dating, they determined that those plants have been frozen for 500 years since the Little Ice Age when the glacier was at its maximum.
The most surprising thing, however, was that many of the plants were showing signs of life: they had green tips and fresh off-shoots, even though they have only been ice-free for less than a year and were just a few centimeters away from the glacier margin.
Plants have long been reported to emerge from beneath Arctic glacier ice. One study from 1966 stated that "vigorous new moss shoots appear in places to be growing directly out of the underlying dead moss." It concluded the new growth was a result of germination of either dormant or migrant spores on the "dead moss mats."
That and all other publications since then, presumed that the emergent vegetation was dead. Now for the first time, researchers realized that at least part of that re-growth is coming from the Ice Age plants themselves. "This is an important distinction," explains the lead scientist Dr. Catherine La Farge from University of Alberta.
To confirm their observations in the field, the team of scientists collected samples of these recently uncovered plants and grew them in the lab under careful monitoring. The results were unprecedented: a third of the plants re-grew! The discovery was reported in the prestigious journal Proceeding of the National Academy of Sciences (PNAS) this week.
The second important finding about this scientific discovery is that the plant cells grown in the lab acted as stem cells: they were capable of regenerating the entire plant regardless of which part of the body did the original cell come from. This capability is known as totipotency.
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Plants under snow image via Shutterstock.