By Laura Shin | February 21, 2012, 5:46 AM PST
The results were published by Svetlana Yashina and David Gilichinsky of the Russian Academy of Sciences research center at Pushchino, near Moscow, in The Proceedings of the National Academy of Sciences of the U.S.
How they did it
The researchers excavated ancient squirrel burrows along the bank of the lower Kolyma River, which, during the last ice age, was home to mammoth and woolly rhinoceroses. The ground there was permanently frozen at minus 7 degrees Celsius.
Some of the burrow’s storage areas held more than 600,000 seeds and fruits.
The researchers first tried but failed to germinate the narrow-leafed campion (Silene stenophylla) from seeds. They then took cells from the placenta, the fruit’s seed-producing organ, and grew them in culture dishes; three of them produced 36 plants.
The ancient plants seemed identical to modern-day narrow-leafed campions until they flowered, when their petals came out narrower and more spaced- out. The New York Times reports, “Seeds from the ancient plants germinated with 100 percent success, compared with 90 percent for seeds from living campions.”
Radiocarbon dating is key
The Russian team got a radiocarbon dating of 31,800 years from seeds attached to the same placenta whose cells produced the revived plants.
The radiocarbon date is key because past claims of ancient plants revived were later debunked. For instance, lupines were generated from seeds in a 10,000-year-old lemming burrow in the Yukon, but radiocarbon dating later showed the seeds were modern ones that had infiltrated the site.
The researchers suggest the incredible longevity of the campion plant cells may be due to several factors. First, squirrels store their food next to permafrost so seeds remain cool during the arctic summers. This means the fruits would have been chilled from the very beginning. Also, the Times reports, “The fruit’s placenta contains high levels of sucrose and phenols, which are good antifreeze agents.”
Additionally, the site had low levels of ground radioactivity, which can damage DNA. The amount of gamma radiation the campion fruit accumulated over 30,000 years is only a bit higher than that reported for another ancient seed that produced a live plant: a 1,300-year-old sacred lotus seed.