University of Alberta researchers led by Dr Catherine La
Farge have brought back to life 400 year old frozen mosses recovered
from melting glaciers in the High Canadian Arctic.
FROM:
Lab
cultures of Little Ice Age bryophytes: the turgid aulacomnium moss
Aulacomnium turgidum with the moss Distichium capillaceum and
Ptychostomum sp. Scale bar – 15 mm (Catherine La Farge et al)
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The result, reported in the Proceedings of the National Academy of Sciences,
overturns a long-held assumption that all of the plant remains exposed
by retreating polar glaciers are dead. Previously, any new growth of
plants close to the glacier margin was considered the result of rapid
colonization by modern plants surrounding the glacier.
Dr La Farge’s team using radiocarbon dating confirmed that the
plants, which ranged from 400 to 600 years old, were entombed during the
Little Ice Age that happened between 1550 and 1850.
In the field, the scientists noticed that the subglacial populations
were not only intact, but also in pristine condition – with some
suggesting regrowth.
They then selected 24 subglacial samples for culture experiments.
Seven of these samples produced 11 cultures that successfully
regenerated four species from the original parent material, including
the turgid aulacomnium moss
Aulacomnium turgidum and the moss
Distichium capillaceum.
“The re-growth of these Little Ice Age bryophytes (such as mosses and
liverworts) expands our understanding of glacier ecosystems as
biological reservoirs that are becoming increasingly important with
global ice retreat,” Dr La Farge said.
“We know that bryophytes can remain dormant for many years and then
are reactivated, but nobody expected them to rejuvenate after nearly 400
years beneath a glacier.”
“These simple, efficient plants, which have been around for more than
400 million years, have evolved a unique biology for optimal
resilience. Any bryophyte cell can reprogram itself to initiate the
development of an entire new plant. This is equivalent to stem cells in
faunal systems.”
Dr La Farge said: “the finding amplifies the critical role of
bryophytes in polar environments and has implications for all permafrost
regions of the globe.”
“Bryophytes are extremophiles that can thrive where other plants do
not, hence they play a vital role in the establishment, colonization and
maintenance of polar ecosystems.”
“This discovery emphasizes the importance of research that helps us
understand the natural world, given how little we still know about polar
ecosystems – with applied spin-offs for understanding reclamation that
we may never have anticipated.”
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Bibliographic information: Catherine La
Farge et al. Regeneration of Little Ice Age bryophytes emerging from a
polar glacier with implications of totipotency in extreme environments. PNAS, published online before print May 28, 2013; doi: 10.1073/pnas.1304199110
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